Protein Metabolism

High temperature tolerance has been genetically engineered in plants mainly by over-expressing the heat shock protein genes or indirectly by altering levels of heat shock transcription factor proteins. Apart from heat shock proteins, thermotolerance has also been altered by elevating levels of osmolytes, increasing levels of cell detoxification enzymes and through altering membrane fluidity. It is suggested that Hsps may be directly implicated in thermotolerance as agents that minimize damage to cell proteins. The other three above approaches leading to thermotolerance in transgenic experiments though operate in their own specific ways but indirectly might be aiding in creation of more reductive and energy-rich cellular environment, thereby minimizing the accumulation of damaged proteins. Intervention in protein metabolism such that accumulation of damaged proteins is minimized thus appears to be the main target for genetically-engineering crops against high temperature stress.

Improvement in the osmoregulation capacity via nutritional supplies is vitally important in shrimp aquaculture. The effects of dietary protein levels on the osmoregulation capacity of the Pacific white shrimp (L. vannamei) were investigated. This involved an examination of growth performance, glutamate dehydrogenase (GDH) and Na + -K + ATPase mRNA expression,, and GDH activity in muscles and gills. Three experimental diets were formulated, containing 25%, 40%, and 50% dietary protein, and fed to the shrimp at a salinity of 25. After 20 days, no significant difference was observed in weight gain, though GDH and Na + -K + ATPase gene expression and GDH activity increased with higher dietary protein levels. Subsequently, shrimp fed diets with 25% and 50% dietary protein were transferred into tanks with salinities of 38 and 5, respectively, and sampled at weeks 1 and 2. Shrimp fed with 40% protein at 25 in salinity (optimal conditions) were used as a control. Regardless of the salinities, shrimp fed with 50% dietary protein had significantly higher growth performance than other diets; no significant differences were found in comparison with the control. Shrimp fed with 25% dietary protein and maintained at salinities of 38 and 5 had significantly lower weight gain values after 2 weeks. Ambient salinity change also stimulated the hepatosomatic index, which increased in the first week and then recovered to a relatively normal level, as in the control, after 2 weeks. These findings indicate that in white shrimp, the specific protein nutrient and energy demands related to ambient salinity change are associated with protein metabolism. Increased dietary protein level could improve the osmoregulation capacity of L. vannamei with more energy resources allocated to GDH activity and expression.

Enteral and parenteral glutamine supplementation in preterm infants has been shown to have some beneficial effects on neonatal morbidity and mortality, although the results are controversial. In this study, we aimed to determine if long-term glutamine-supplemented enteral nutrition affects growth parameters in very-low-birth-weight (VLBW) preterm infants. Preterm infants with a birth weight of < or = 1500 g were assigned to receive enteral glutamine supplementation (300 mg/kg/day) or placebo between 8-120 days (4 months) of life. At the end of each month, growth parameters [weight, length, head circumference, left upper mid-arm circumference (MAC) and left mid-thigh circumference (MTC)] were determined and enteral glutamine dose was adjusted according to the current weight. In VLBW infants (n = 69), the glutamine-supplemented group (n = 36) had significantly higher mean weight, length, head circumference, MAC and MTC than the control group (n=33) at the end of the fourth month. T...

Oxidative stress represents an imbalance between reactive oxygen species (ROS) and cellular mechanisms for detoxifying the reactive intermediates or repairing the resulting damage, in this study oxidative stress was evaluated by anti-Mda antibodies that directed against malondialdhyde (Mda) in different placental regions (cord insertion, central, and peripheral) in different age groups (preterm, term, and postdate), and correlated with syncytial apoptosis expressed as syncytial knots count that stained with Tunel stain. A significant variation was found in anti-Mda antibody among age groups in all placental regions and syncytial knots count in peripheral region only at p≤0.05, with a highly significant positive correlation between syncytial knot counts and oxidative stress in peripheral region at termat r.0.811, and significant negative correlation at r.0.003 in postdate group in peripheral region. We conclude that oxidative stress play a major role in syncytial apoptosis as formati...

The hulothane genotype of 22 Polish landrace pigs wus determined using huko t&e test and hkood typing. Eigh I horz~~,~ous nonncrl ( NN) , eight herero-zygotes ( Nn) und six homo~ygous recessive (nn) were ident{fied. The kv~ls of ~iy~o~gurr md hta tt' were vncuwvd it1 biopsy samples taken jhn the longissimus lumborum using (I shot biopsy tcvhique. pH(pN,) trnd IMPlATP r'utio ( R) were determined uf 30 rnin after sh.q$tsr, rvhikc pN, meut colour und waler holding capacity were determined on the duy ufter sluughter. The halothune genotype did not @eel intra vitam glycogen level. The nn pigs hud a higher R vuiue and lower pH, than both Nn und NN animals. Heterozygous unimuls were intermediute hetwcen both homo-zygotes for biopsy iuctate level and meat coolour. The luclate content oJ' biopsy sumples was signl@antly correlated with pH, (r of: -068; P<O.Ol), R (r = 068; P<OuOl), meat colour (r = O-57; P~0.01) und wuter holding cupucify (r = 0.45; P < 0.05).

Background: Animals' digestive tract represents the functional link between foraging and the energy available for survival, growth, and reproduction. In addition, gut tissue is one of the most expensive tissues to maintain in terms of energy and protein metabolism. Thus, gut size flexibility has been suggested to be one of the most important physiological adjustments to cope with changes in environmental conditions. Hypotheses: (1) Animals adjust their digestive features to cope with changing environmental conditions, and increase gut size in parallel to increased food consumption. (2) Changes in different energy-demanding factors, such as lactation, pregnancy, and temperature, determine different magnitudes of gut size flexibility. (3) Changes in the amount of undigestible material in the diet mainly affect the size of the fermentative chambers, while changes in energy demands mainly affect the size of the small intestine. (4) The qualities of a demand, such as its relative intensity or duration, affect the amount of digestive flexibility. Data incorporated: We focus on digestive organ length and dry mass of laboratory mice (Mus musculus) and white rats (Rattus norvegicus). We found and reviewed 25 studies that reported a total of 55 comparisons for small intestine length, 67 for small intestine dry mass, 25 for hindgut length, and 26 for hindgut dry mass. We conducted a meta-analysis in which we calculated the Hedges difference for each comparison, and using mixed-effects models plus heterogeneity tests to evaluate differences among factors. Results: Although gut size flexibility was noted for all the experimental factors evaluated, there was variation in the amount of digestive flexibility determined by each factor. Changes in large intestine length were greater for changes in diet quality than for changes in energy-demanding factors, but this result was not observed for large intestine mass. A clear correlation between gut size flexibility and the number of pups reared during lactation was recorded. Conclusions: The present analysis confirms previous hypotheses on gut size flexibility, providing strong quantitative support for them.

This study investigates the impact of chlorpyrifos, an organophosphate pesticide, on the DNA content in various tissues of Channa punctatus, a freshwater fish, over exposure periods of 24, 48, and 96 hours at both sub-lethal and lethal concentrations. The objective was to assess the genotoxic effects of chlorpyrifos through changes in nucleic acid levels, which serve as biomarkers for cellular damage and metabolic activity. Results indicate significant time-and dose-dependent reductions in DNA content across all examined tissues, with the liver and gills showing notable sensitivity. The findings highlight the adverse effects of chlorpyrifos on fish health and underscore its ecological risks in aquatic environments, emphasizing the need for effective monitoring and regulation of pesticide use.

Young animals utilize their dietary amino acids more efficiently for growth because they are capable of a greater increase in tissue protein synthesis in response to feeding than older animals. This response to feeding is particularly profound in skeletal muscle. The feeding-induced stimulation of protein synthesis in skeletal muscle is uniquely and independently regulated by both insulin and amino acids. In most visceral tissues, the stimulation of protein synthesis by feeding is mediated by amino acids alone and not by insulin. The stimulation of protein synthesis by nutrition and hormones is regulated by alterations in the expression and activity of components of the intracellular signaling pathways that control the initiation of translation.

Cirrhosis is characterized by altered lipid and protein metabolism and an excessive accumulation of extracellular matrix components. The aim of this work was to determine the effect of dietary nucleotide intake on the intracellular pools of nucleic acids and nucleotides, hepatic redox state, and protein synthesis during cirrhosis. Rats were given 300 mg/L thioacetamide (TAA) in drinking water and were fed diets without (TAA-Nt) or with nucleotides (Nt) (TAA+Nt, 3 g each of AMP, inosine 5&#39;-monophosphate, CMP, GMP, and UMP per kg diet) for 4 mo. The degree of liver histological injury was less in group TAA+Nt than in TAA-Nt. The intake of nucleotides significantly increased the hepatic concentration of total nucleotides, adenine nucleotides, and ATP+ADP+AMP. Interestingly, the concentration of CDP-choline, a nucleotide necessary for phospholipid synthesis, was significantly higher in TAA+Nt than in TAA-Nt. The hepatic pyruvate:lactate (P = 0.075) and acetoacetate:beta-hydrodybutyr...

Flavescence dorée (FD) is a severe epidemic disease of grapevines caused by FD phytoplasma (FDP) transmitted by the leafhopper vector Scaphoideus titanus. The recent sequencing of the 647-kbp FDP genome highlighted an unusual number of genes encoding ATP-dependent zinc proteases FtsH, which have been linked to variations in the virulence of "Candidatus Phytoplasma mali" strains. The aims of the present study were to predict the FtsH repertoire of FDP, to predict the functional domains and topologies of the encoded proteins in the phytoplasma membrane and to measure the expression profiles in different hosts. Eight complete ftsH genes have been identified in the FDP genome. In addition to ftsH6, which appeared to be the original bacterial ortholog, the other seven gene copies were clustered on a common distinct phylogenetic branch, suggesting intra-genome duplication of ftsH. The expression of these proteins, quantified in plants and insect vectors in natural and experimental pathosystems, appeared to be modulated in a host-dependent manner. Two of the eight FtsH C-tails were predicted by Phobius software to be extracellular and, therefore, in direct contact with the host cellular content. As phytoplasmas cannot synthesize amino acids, our data raised questions regarding the involvement of FtsH in the adaptation to hosts via potentially enhanced recycling of phytoplasma cellular proteins and host protein degradation.

Left untreated, phenylketonuria biochemically results in high phenylalanine concentrations in blood and tissues, and clinically especially in severe mental retardation. Treatment consists of severe dietary restriction of phenylalanine with more or less normal intellectual outcome as result when started early enough. It is unclear whether treatment for life is necessary. A clear relationship between plasma phenylalanine concentrations and cerebral outcome exists, but the precise pathophysiological mechanism is not understood. In studies in mice with phenylketonuria, the cerebral protein synthesis rate is decreased when compared to controls. The aim of the present study was to determine the protein synthesis rate in relation to the plasma phenylalanine concentrations in-vivo in patients with phenylketonuria by positron emission tomography brain studies after an intravenous L-[1-11 C]-tyrosine bolus. Results showed a significant negative relationship (R 2 = 0.40, p < 0.01) between plasma phenylalanine concentration and the cerebral protein synthesis rate in 19 patients with phenylketonuria. At increased plasma phenylalanine concentrations, i.e. above 600-800 lmol/l, the cerebral protein synthesis rate is clearly decreased compared to lower phenylalanine concentrations. These data suggest that cerebral protein metabolism in untreated adults with phenylketonuria can be abnormal due to high plasma phenylalanine concentrations. Hence, we speculate that it is important to continue dietary treatment into adulthood, aiming at plasma phenylalanine concentrations <600-800 lmol/l.

Left untreated, phenylketonuria biochemically results in high phenylalanine concentrations in blood and tissues, and clinically especially in severe mental retardation. Treatment consists of severe dietary restriction of phenylalanine with more or less normal intellectual outcome as result when started early enough. It is unclear whether treatment for life is necessary. A clear relationship between plasma phenylalanine concentrations and cerebral outcome exists, but the precise pathophysiological mechanism is not understood. In studies in mice with phenylketonuria, the cerebral protein synthesis rate is decreased when compared to controls. The aim of the present study was to determine the protein synthesis rate in relation to the plasma phenylalanine concentrations in-vivo in patients with phenylketonuria by positron emission tomography brain studies after an intravenous L-[1-11 C]-tyrosine bolus. Results showed a significant negative relationship (R 2 = 0.40, p < 0.01) between plasma phenylalanine concentration and the cerebral protein synthesis rate in 19 patients with phenylketonuria. At increased plasma phenylalanine concentrations, i.e. above 600-800 lmol/l, the cerebral protein synthesis rate is clearly decreased compared to lower phenylalanine concentrations. These data suggest that cerebral protein metabolism in untreated adults with phenylketonuria can be abnormal due to high plasma phenylalanine concentrations. Hence, we speculate that it is important to continue dietary treatment into adulthood, aiming at plasma phenylalanine concentrations <600-800 lmol/l.

The high efficiency of protein deposition during the neonatal period is driven by high rates of protein synthesis, which are maximally stimulated after feeding. In the current study, we examined the individual roles of amino acids and insulin in the regulation of protein synthesis in peripheral and visceral tissues of the neonate by performing pancreatic glucose-amino acid clamps in overnightfasted 7-day-old pigs. We infused pigs (n = 8-12/group) with insulin at 0, 10, 22, and 110 ng kg -0.66 min -1 to achieve ~0, 2, 6 and 30 μU ml -1 insulin so as to simulate below fasting, fasting, intermediate, and fed insulin levels, respectively. At each insulin dose, amino acids were maintained at the fasting or fed level. In conjunction with the highest insulin dose, amino acids were also allowed to fall below the fasting level. Tissue protein synthesis was measured using a flooding dose of L-[4-3 H] phenylalanine. Both insulin and amino acids increased fractional rates of protein synthesis in longissimus dorsi, gastrocnemius, masseter, and diaphragm muscles. Insulin, but not amino acids, increased protein synthesis in the skin. Amino acids, but not insulin, increased protein synthesis in the liver, pancreas, spleen, and lung and tended to increase protein synthesis in the jejunum and kidney. Neither insulin nor amino acids altered protein synthesis in the stomach. The results suggest that the stimulation of protein synthesis by feeding in most tissues of the neonate is regulated by the

The timing of moult in birds is thought to be constrained by physiological trade-offs. We studied barn swallows in central Spain to assess whether (a) body moult tends to be temporally separated from migration in adult and first-year birds, (b) it is related to an impaired fattening, and (c) its overlap with migration may involve adverse energetic effects. First-year swallows tended to moult early in the post-breeding period: the proportion of first-year birds in active moult was highest in July, and it decreased progressively until September. On the other hand, adult swallows tended to avoid moulting both in the post-breeding (July) and the migratory period (September), concentrating their moulting period in August. In all periods, swallows in active moult stored less fat than non-moulting ones, suggesting a faster depletion of energy resources by moulting birds. Swallows in active moult showed a better body condition -measured as body mass relative to body size and fat content -than nonmoulting ones before migration (coinciding with the periods of highest frequency of moulting individuals), but the opposite was found during autumn migration. Our results support the existence of a physiological trade-off between body moult and migration, which could have fitness consequences; thus, if these activities overlap it would impair migration performance of swallows.

observaram o desenvolvimento de sabor amargo e metálico em carne injetada com solução 300mM de cloreto de cálcio. Assim, é importante estabelecer a concentração e quantidade ideal de CaCl2 a ser adicionado à carne para obter o efeito desejado de abrandamento da textura, sem promover o surgimento de defeitos de sabor decorrentes da aplicação dessa alternativa tecnológica. É muito importante o entendimento das bases bioquímicas no processo de amaciamento da carne durante a maturação, já que esta é uma ferramenta que melhora as suas características organolépticas, apresentando um produto de melhor qualidade para o consumidor e aumentando o seu valor de mercado.

Glucocorticoids (GCs) exert key metabolic influences on skeletal muscle. GCs increase protein degradation and decrease protein synthesis. The released amino acids are mobilized from skeletal muscle to liver, where they serve as substrates for hepatic gluconeogenesis. This metabolic response is critical for mammals' survival under stressful conditions, such as fasting and starvation. GCs suppress insulin-stimulated glucose uptake and utilization and glycogen synthesis, and play a permissive role for catecholamineinduced glycogenolysis, thus preserving the level of circulating glucose, the major energy source for the brain. However, chronic or excess exposure of GCs can induce muscle atrophy and insulin resistance. GCs convey their signal mainly through the intracellular glucocorticoid receptor (GR). While GR can act through different mechanisms, one of its major actions is to regulate the transcription of its primary target genes through genomic glucocorticoid response elements (GREs) by directly binding to DNA or tethering onto other DNA-binding transcription factors. These GR primary targets trigger physiological and pathological responses of GCs. Much progress has been made to understand how GCs regulate protein and glucose metabolism. In this review, we will discuss how GR primary target genes confer metabolic functions of GCs, and the mechanisms governing the transcriptional regulation of these targets. Comprehending these processes not only contributes to the fundamental understanding of mammalian physiology, but also will provide invaluable insight for improved GC therapeutics.

Rates of whole-body protein turnover and energy expenditure were measured in two groups of wethers differing in estimated breeding values (EBVs) for wool growth, but with similar EBVs for fibre diameter and liveweight (LW). The sheep were offered a pelleted diet at 1.2 times their metabolisable energy (ME) requirement for maintenance (1.2 M) followed by either 0.8 M or 1.8 M for 5 weeks. In the 5th week, whole-body protein metabolism was estimated by using intravenous injection of 15N-glycine (g N/day) and whole-body energy expenditure rate (EE) was predicted by the CO2 entry rate technique using intravenous injection of NaH13CO3. The higher N intake (8.7 v. 20.4 g N/day, P &lt; 0.001) was associated with a higher whole-body protein flux (22.1 v. 34.2 g N/day, P &lt; 0.001), and a higher whole-body protein synthesis rate (17.0 v. 25.5 g N/day, P &lt; 0.001) and protein degradation rate (15.9 v. 20.7 g N/day, P &lt; 0.001). Irrespective of feeding levels, sheep with high-fleece EBVs ...

In Alzheimer’s disease (AD) amyloid-β (Aβ) deposits may cause impairments in choroid plexus, a specialised brain structure which forms the blood–cerebrospinal fluid (CSF) barrier. We previously carried out a mass proteomic-based study in choroid plexus from AD patients and we found several differentially regulated proteins compared with healthy subjects. One of these proteins, annexin A5, was previously demonstrated implicated in blocking Aβ-induced cytotoxicity in neuronal cell cultures. Here, we investigated the effects of annexin A5 on Aβ toxicity in choroid plexus. We used choroid plexus tissue samples and CSF from mild cognitive impairment (MCI) and AD patients to analyse Aβ accumulation, cell death and annexin A5 levels compared with control subjects. Choroid plexus cell cultures from rats were used to analyse annexin A5 effects on Aβ-induced cytotoxicity. AD choroid plexus exhibited progressive reduction of annexin A5 levels along with progressive increased Aβ accumulation an...

The b site APP cleaving enzyme 1 (BACE1) is the rate-limiting b-secretase enzyme in the amyloidogenic processing of APP and Ab formation, and therefore it has a prominent role in Alzheimer's disease (AD) pathology. Recent evidence suggests that the prion protein (PrP) interacts directly with BACE1 regulating its b-secretase activity. Moreover, PrP has been proposed as the cellular receptor involved in the impairment of synaptic plasticity and toxicity caused by Ab oligomers. Provided that common pathophysiologic mechanisms are shared by Alzheimer's and Creutzfeldt-Jakob (CJD) diseases, we investigated for the first time to the best of our knowledge a possible association of a common synonymous BACE1 polymorphism (rs638405) with sporadic CJD (sCJD). Our results indicate that BACE1 C-allele is associated with an increased risk for developing sCJD, mainly in PRNP M129M homozygous subjects with early onset. These results extend the very short list of genes (other than PRNP) involved in the development of human prion diseases; and support the notion that similar to AD, in sCJD several loci may contribute with modest overall effects to disease risk. These findings underscore the interplay in both pathologies of APP, Ab oligomers, ApoE, PrP and BACE1, and suggest that aging and perhaps vascular risk factors may modulate disease pathologies in part through these key players.

Aims Recent studies suggest that atrial fibrillation (AF) substantially influences microvascular flow in ventricular myocardium. This process may contribute to the occurrence of heart failure in AF. In general, development of heart failure and renal dysfunction go hand-in-hand causing systemic fluid overload and oedema. So far, it is unknown whether AF itself influences renal function. The aim of the present study was to determine the impact of AF on renal gene expression in a closed chest rapid atrial pacing model. Methods and results A total of 14 pigs were studied. In five pigs, rapid atrial pacing (AT) was performed for 7 h (600 bpm); in five additional animals, rapid atrial pacing was performed in the presence of irbesartan infusion (irbesartan group). Four pigs were instrumented without interventions (sham). After the pacing period, renal expression of collagen Ia1 and Ia3, transforming growth factor-b (TGF-b), neutral endopeptidase (NEP; the main enzyme involved in natriuretic protein metabolism), and atrial natriuretic peptide (ANP) were determined by RT-PCR and immunoblot analysis. Functional in vitro experiments were performed using HEK-293 kidney cells. Renal mRNA expression of NEP was substantially downregulated during AT (AT: 12.7 + 9.3% vs. sham: 100 + 43.4%; P , 0.01). Results at the mRNA level were confirmed at the protein level. Irbesartan therapy did not prevent down-regulation of NEP. In contrast, TGF-b1 mRNA expression was up-regulated (AT: 208.5 + 79.3% vs. sham: 100 + 34.6% P , 0.05). Collagen and angiotensin II type 1 receptor (AT1R) expression were not significantly altered by AT. HEK-293 cells were used to determine the potential humoral factors involved in down-regulation of NEP. Application of aldosterone, ANP, asymmetric dimethylarginine, and angiotensin peptides failed to cause down-regulation of renal NEP expression in vitro. Conclusion AT reduces NEP expression and stimulates TGF-b1 signalling in the kidneys. Thus, even brief episodes of AT affect renal gene expression, which may account for structural renal changes and alterations of renal function in the long term.

The objective of this experiment was to determine the protocol of enzymatic products utilization according to the wheat and barley proportion in the compound feed used in broilers. We used this experiment to analyze the anti-nutritional NSP’s effect of the wheat introduced in the compound feed in a proportion of 60 % and also of the compound feed including wheat in a proportion of 30 % and barley in a proportion of 30 %, on the digestive indices in broilers. To these, we added the variants with introduction of xylanase, in an amount of 100 ppm, and to counteract the anti-nutritional effect of the wheat and barley-based NSP, we introduced 50 ppm xylanase and 50 ppm beta glucanase. We also determined the coefficients of correlation between the digestive coefficient values (intestinal viscosity) and the soluble, insoluble and total NSP contents. The introduction of the wheat-specific enzyme in compound feed in a proportion of 60 % (LE3) or 30 % wheat and 30 % barley (LE5) determine vis...

Leucine irreversible loss (ILR) and fractional leucine oxidation (FO) were estimated using primed infusions of L-[1-13C]leucine and [13C]bicarbonate. Feed restriction decreased (P &lt; 0.05) ILR from 16.42 to 10.82 mmol h−1, but did not affect FO (0.172) in two young dairy heifers. In six growing steers, ILR and FO averaged 30.03 ± 5.09 mmol h−1 and 0.147 ± 0.027, respectively. L-[1-13C]leucine and [13C]bicarbonate can be successfully used to measure the different components of protein metabolism in cattle. Key words: Stable isotope, protein metabolism, leucine, bicarbonate, cattle

The ever increasing burden of an aging population and pandemic of metabolic syndrome worldwide demands further understanding of the modifiable risk factors in reducing disability and morbidity associated with these conditions. Disuse skeletal muscle atrophy (sometimes referred to as "simple" atrophy) and insulin resistance are "non-pathological" events resulting from sedentary behavior and periods of enforced immobilization e.g., due to fractures or elective orthopedic surgery. Yet, the processes and drivers regulating disuse atrophy and insulin resistance and the associated molecular events remain unclear-especially in humans. The aim of this review is to present current knowledge of relationships between muscle protein turnover, insulin resistance and muscle atrophy during disuse, principally in humans. Immobilization lowers fasted state muscle protein synthesis (MPS) and induces fed-state "anabolic resistance." While a lack of dynamic measurements of muscle protein breakdown (MPB) precludes defining a definitive role for MPB in disuse atrophy, some proteolytic "marker" studies (e.g., MPB genes) suggest a potential early elevation. Immobilization also induces muscle insulin resistance (IR). Moreover, the trajectory of muscle atrophy appears to be accelerated in persistent IR states (e.g., Type II diabetes), suggesting IR may contribute to muscle disuse atrophy under these conditions. Nonetheless, the role of differences in insulin sensitivity across distinct muscle groups and its effects on rates of atrophy remains unclear. Multifaceted time-course studies into the collective role of insulin resistance and muscle protein turnover in the setting of disuse muscle atrophy, in humans, are needed to facilitate the development of appropriate countermeasures and efficacious rehabilitation protocols.

Aims: Free radicals may not only affect the denatured cell structure but also reduce protein levels. These mechanisms are critical and need to be clarified as a high priority. Because of the limited information on this subject, in this respect, the effects on protein levels of liver tissue in rats fed hot-smoked rainbow trout (Oncorhynchus mykiss) were investigated. Methods:Four diets containing fresh and hot-smoked rainbow trout flesh and vitamins were prepared and commercial pellet food was purchased. Four groups of female Wistar rats were fed the diets for 28 days. The rats were killed by decapitation, and the hepatic tissue was removed. Total protein and detection of protein bands using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were evaluated. Results:The liver protein level in rats fed a hot-smoked rainbow trout flesh + vitamin diet was increased significantly compared with the other diet groups (p &lt; 0.001, p &lt; 0.009 and p &lt; 0.011). 10 protei...

Aim: In this study, we aimed to evaluate the effectiveness of an educational intervention in patients with liver cirrhosis. Background: Liver cirrhosis is end stage of liver diseases with many complications that affects quality of life and nutritional status in cirrhotic patients. Today, educational intervention and nutritional counseling is a key factor for preventing disease process and improving quality of life in patients with chronic diseases. Methods: This quasi-experimental, non-randomized, pre and post intervention were conducted as a pilot study on cirrhotic patients. Educational intervention and nutritional counseling were performed in clinical visits and via guide booklet. Chronic liver disease questionnaire (CLDQ) and knowledge questionnaire were used to assess patients' quality of life and knowledge. Blood samples were taken before and after intervention for assessment of laboratory outcomes. Results: One hundred and seven patients referred to Research Center for enrolling in the trial. Twenty-eight did not meet inclusion criteria and seven patients were excluded from the study for lack of proper follow-up. Final analyses were done on 72 patients. Quality of life and knowledge of cirrhotic patients improved significantly after educational intervention (P < 0.0001). Biochemical characteristics were not changed significantly. Ascites and edema were improved significantly (P = 0.005 and P = 0.002, respectively). There was significant difference before and after intervention in the days of hospitalization (P = 0.001). Conclusion: We concluded a simple educational intervention and continuous monitoring for 6 months can affect clinical outcomes, quality of life, hospital admissions days, and knowledge of patients with cirrhosis.

Food-induced morphological plasticity, a type of developmental plasticity, is a well-documented phenomenon in larvae of the echinoid echinoderm, Dendraster excentricus. A recent study in our lab has shown that this morphological plasticity is associated with significant physiological plasticity for growth. The goal of the current study was to measure several aspects of protein metabolism in larvae growing at different rates to understand the mechanistic basis for this physiological growth plasticity. Larvae of D. excentricus were fed rations of 1,000 (low-fed) or 10,000 (high-fed) algal cells mL -1 . Primary measurements of protein growth, algal ingestion, aerobic metabolism, alanine transport and protein synthesis were used to model growth and protein metabolism. Relative protein growth rates were 6.0 and 12.2 % day -1 for low-and highfed larvae, respectively. The energetic cost of protein synthesis was similar between both treatments at 4.91 J (mg protein synthesized) -1 . Larvae in both treatments used about 50% of their metabolic energy production to fuel protein synthesis. Mass-specific rates of protein synthesis were also similar. The most important difference between low-and high-fed larvae were mass-specific rates of protein degradation. Low-fed larvae had relatively low rates of degradation early in development that increased with larval age, surpassing high-fed degradation rates at 20 days post-fertilization. Changes in protein depositional efficiency during development were similar to those of larval growth efficiency, indicating that differences in protein metabolism are largely responsible for whole-organism growth plasticity. Mass-specific alanine transport rates were about 2-times higher in low-fed larvae, demonstrating that the longer arms of low-fed larvae may be a mechanism for acquiring more dissolved nutrients from their environment. In total, these results provide an explanation for the differences in growth efficiency between low-and high-fed larvae and demonstrate the importance of protein degradation pathways in establishing these growth differences. These observations, together with previous studies measuring morphological and physiological plastic responses, allow for a more integrated understanding of developmental plasticity in echinoid larvae.

Food-induced morphological plasticity, a type of developmental plasticity, is a well-documented phenomenon in larvae of the echinoid echinoderm,Dendraster excentricus. A recent study in our lab has shown that this morphological plasticity is associated with significant physiological plasticity for growth. The goal of the current study was to measure several aspects of protein metabolism in larvae growing at different rates to understand the mechanistic basis for this physiological growth plasticity. Larvae ofD. excentricuswere fed rations of 1,000 (low-fed) or 10,000 (high-fed) algal cells mL−1. Primary measurements of protein growth, algal ingestion, aerobic metabolism, alanine transport and protein synthesis were used to model growth and protein metabolism. Relative protein growth rates were 6.0 and 12.2 % day−1for low- and high-fed larvae, respectively. The energetic cost of protein synthesis was similar between both treatments at 4.91 J (mg protein synthesized)−1. Larvae in both...

Background: Pathogenic factors that cause a child to develop the edematous instead of the nonedematous form of severe childhood undernutrition (SCU) during food deprivation are not clear. It was hypothesized that, in edematous but not nonedematous SCU, impaired protein breakdown leading to inadequate amino acids for maintenance of important organ systems was a factor. Objective: We measured protein kinetics in children with edematous and nonedematous SCU. Design: Endogenous leucine flux, an index of whole-body protein breakdown rate, was determined in 4 groups of children with edematous or nonedematous SCU in the malnourished and recovered states. Two groups were studied in the postabsorptive state, and 2 groups were studied in the fed state. Results: In the postabsorptive state, leucine flux was slower (P 0.01) in the edematous group than in the nonedematous group in the malnourished state, but in the recovered state, it was faster (P 0.05) in the children who previously had edematous SCU. When compared with the malnourished state value, leucine flux at recovery doubled in the group that previously had edematous SCU, but it did not change in the other group. In the fed state, leucine flux was slower (P 0.01) in the edematous group than in the nonedematous group in the malnourished state but not in the recovered state. In the recovered state, enteral leucine extraction by splanchnic tissues trended higher in the group that previously had edematous SCU than in the nonedematous group. These findings indicate different protein breakdown responses to food deprivation between children with edematous and nonedematous SCU and inherent differences in protein metabolism when they have recovered.

Several studies have demonstrated that a maternal low-protein diet induces long-term metabolic disorders, but the involved mechanisms are unclear. This study investigated the molecular effects of a low-protein diet during pregnancy and lactation on glucose and protein metabolism in soleus muscle isolated from adult male rats. Female rats were fed either a normal protein diet or low-protein diet during gestation and lactation. After weaning, all pups were fed a normal protein diet until the 210th day postpartum. In the 7th month of life, mass, contractile function, protein and glucose metabolism, and the Akt-mTOR pathway were measured in the soleus muscles of male pups. Dry weight and contractile function of soleus muscle in the lowprotein diet group rats were found to be lower compared to the control group. Lipid synthesis was evaluated by measuring palmitate incorporation in white adipose tissue. Palmitate incorporation was higher in the white adipose tissue of the low-protein diet group. When incubated soleus muscles were stimulated with insulin, protein synthesis, total amino acid incorporation and free amino acid content, glucose incorporation and uptake, and glycogen synthesis were found to be reduced in low-protein diet group rats. Fasting glycemia was higher in the low-protein diet group. These metabolic changes were associated with a decrease in Akt and GSK-3β signaling responses to Frontiers in Nutrition

Complete clinical expression of the HFE1 hemochromatosis is very likely modulated by genes linked to duodenal iron absorption, whose level is conditioned by unknown processes taking place during enterocyte differentiation. We carried out a transcriptomic study on CaCo-2 cells used as a model of enterocyte differentiation in vitro. Of the 720 genes on the microarrays, 80, 50, and 56 were significantly downregulated, up-regulated, and invariant during differentiation. With regard to iron metabolism, we showed that HEPH, SLC11A2, SLC11A3, and TF are significantly up-regulated, while ATP7B and SLC39A1 (and SFT) are down-regulated and ACO1, dCYTb, FECH, and FTH1 show constant expression. Ontological annotations highlight the decrease in the expression of cell cycle and DNA metabolism associated genes as well as transcription, protein metabolism, signal transduction, and nucleocytoplasmic transport associated genes, whereas there are increases in the expression of genes linked to cell adhesion, lipid and xenobiotic metabolism, iron transport and homeostasis, and immune response.

Recently, functional state of the liver as a central organ of the body detoxification has been studied as a model of multiple organ dysfunction development in cases of severe experimental trauma. Organ-specific biliation and biligenic functions of the liver are sensitive indicators of its failure and are associated with the declination of the main markers of traumatic disease. The aim of the study -to find out the dynamics of indicators of biligenic function of the liver in response to cranial skeletal trauma associated with haemorrhage. Materials and Methods. Experiments were performed on 54 outbred white male rats, weighing 180-200 g. Animals were divided into three groups: a control one and two experimental. Closed cranio-skeletal injury according to the established technique in our own modification was modelled under thiopental-sodium anaesthesia. A single hit on each hip that caused a closed fracture of femoral bones, was performed by means of an individually designed device. The striking force was 0.375 J, which corresponded to a moderate injury. of the follow-up period they significantly differ from the similar indices of the injured animals with no blood loss. Conclusions. In the presence of experimental cranio-skeletal trauma, the rates of liver biligenic function change up to a maximum declination in 7 days of post-traumatic period. Additional haemorrhage intensifies the revealed abnormalities: the content of total bile acids and cholesterol in bile, as well as the amount of direct bilirubin and the degree of its conjugation in post-traumatic period are significantly lower during the whole period of observation.

The diet is a key environmental factor implicated in health and disease. Oxidative stress, antioxidant status and their relation to diet is a subject of interest in recent years. The objective of the study was to compare lipid peroxidation and antioxidant status in healthy vegetarians and non-vegetarians. The present study comprises 100 healthy individuals (50 vegetarians and 50 non-vegetarians) residing in Belgaum urban area. All the participants were in the age group of 40-60 years of both sexes. This cross-sectional study was done in one year period from April 2007 to March 2008. Malondialdehyde (MDA) (lipid peroxidation product) was estimated by thiobarbituric acid method, glutathione peroxidase by Beutler&#39;s method, Vitamin A and Vitamin E by Bessay et al and Quife et al methods respectively. Our study revealed that the blood MDA level was significantly increased (p value &lt; 0.001) in non-vegetarians compared to lactovegetarians and lacto-ovo-vegetarians. There was signifi...

This paper describes the development of a mechanistic model integrating protein and energy metabolism in preruminant calves of 80-240 kg live weight. The objectives of the model are to gain insight into the partitioning of nutrients in the body of growing calves and to provide a tool for the development of feeding strategies for calves in this weight range. The model simulates the partitioning of nutrients from ingestion through intermediary metabolism to growth, consisting of accretions of protein, fat, ash and water. The model contains 10 state variables, comprising fatty acids, glucose, acetyl-CoA and amino acids as metabolite pools, and fat, ash and protein in muscle, hide, bone and viscera as body constituent pools. Turnover of protein and fat is represented. The model also includes a routine to check possible dietary amino acid imbalance and can be used to predict amino acid requirements on a theoretical basis. The model is based on two experiments, specifically designed for this purpose. Simulations of protein and fat accretion rates over a wide range of nutrient input suggest that the model is sound. It can be used as a research tool and for the development of feeding strategies for preruminant calves.

Nutrition for broilers under high temperatures is extremely important for brazilian broiler chicken industry because the amounts of consumed nutrients and environmental temperature have great effects on bird performance and carcass quality. Among diet nutrients, protein has the highest heat increment; thus, during many years, diets with low protein level were recommended in order to reduce heat production in broiler chickens under heat stress. However, reports have shown that lowprotein diets have negative effects on broiler performance when environmental temperature is high, because during heat stress, low food intake associated to a low diet protein induce amino acid deficiencies. Other studies have shown that broilers fed low-protein diets increase their energy requirement for maintenance with higher heat production. Thus, with the growth of broiler industry in tropical areas more challenges need to be faced by the farmers. So, both the ambient and nutritional conditions ought to be well managed to avoid negative effects on poultry production once they can affect the metabolism (body heat production under low temperature and body heat dissipation under high temperature) with consequence on poultry performance (meat and eggs).

Elevated inflammatory markers and muscle wasting were common in chronic obstructive pulmonary disease (COPD) patients. The purpose of this study was to investigate the effect of 7-day beta-hydroxy-beta-methylbutyrate (HMB) supplementation on inflammation, protein metabolism, and pulmonary function in COPD patients in an intensive care unit. Thirty-four COPD patients who required mechanical ventilators were randomly assigned to HMB (n=18) or control (n=16) groups. The HMB group received HMB 3 g/d for 7 days. White blood cell count, C-reactive protein, and creatinine were significantly lower, while cholesterol and total protein were significantly higher after HMB supplementation. The body weight remained unchanged in both groups. Ten subjects (55.6%) in the HMB group and 4 subjects (25.0%) in the control group had improved pulmonary function, indicated by their ventilator modes. This short-term study suggests that HMB supplementation may have anti-inflammatory and anticatabolic effect...

In Spirodela oligorrhiza, mature chloroplasts copiously synthesize and degrade a 32-kilodalton membrane protein. The rates of synthesis and degradation are controlled by light intensity, the protein being unstable in the light and stable in the dark. Light-driven synthesis, but not degrada- tion, is dependent on ATP. Degradation is blocked by herbi- cides inhibiting photosystem II electron transport, such as diu- ron and atrazine. Thus, both anabolism and catabolism of the 32-kilodalton protein are photoregulated, with degradation coupled to electron transport rather than phosphorylation.

Debate about the optimum balance of macronutrients for adult weight maintenance or weight loss continues to expand. Often this debate centers on the relative merits or risks of carbohydrates vs. fats; however, there is increasing interest in the optimal level of dietary protein for weight loss. Diets with a reduced ratio of carbohydrates/protein are reported to be beneficial for weight loss, although diet studies appear to lack a fundamental hypothesis to support higher protein intakes. Presently, needs for dietary proteins are established by the recommended daily allowance (RDA) as the minimum level of protein necessary to maintain nitrogen balance. The RDA define the primary use of amino acids as substrates for synthesis of body proteins. There is emerging evidence that additional metabolic roles for some amino acids require plasma and intracellular levels above minimum needs for protein synthesis. The branched-chain amino acid leucine is an example of an amino acid with numerous metabolic roles that function in proportion with cellular concentration. This review provides an overview of the current understanding of metabolic roles of leucine and proposes a metabolic framework to evaluate the merits of a higher protein diet for weight loss.

Tendinopathy (TP) is a complex clinical syndrome characterized by local inflammation, pain in the affected area, and loss of performance, preceded by tendon injury. The disease develops in three phases: Inflammatory phase, proliferative phase, and remodeling phase. There are currently no proven treatments for early reversal of this type of injury. However, the metabolic pathways of the transition metabolism, which are necessary for the proper functioning of the organism, are known. These metabolic pathways can be modified by a number of external factors, such as nutritional supplements. In this study, the modulatory effect of four dietary supplements, maslinic acid (MA), hydroxytyrosol (HT), glycine, and aspartate (AA), on hepatic intermediary metabolism was observed in Wistar rats with induced tendinopathy at different stages of the disease. Induced tendinopathy in rats produces alterations in the liver intermediary metabolism. Nutraceutical treatments modify the intermediary metabolism in the different phases of tendinopathy, so AA treatment produced a decrease in carbohydrate metabolism. In lipid metabolism, MA and AA caused a decrease in lipogenesis at the tendinopathy and increased fatty acid oxidation. In protein metabolism, MA treatment increased GDH and AST activity; HT decreased ALT activity; and the AA treatment does not cause any alteration. Use of nutritional supplements of diet could help to regulate the intermediary metabolism in the TP.

Background: Many people believe in favourable effects of branched-chain amino acids (BCAAs; valine, leucine, and isoleucine), especially leucine, on muscle protein balance and consume BCAAs for many years. We determined the effects of the chronic intake of a BCAA-or leucine-enriched diet on protein and amino acid metabolism in fed and postabsorptive states. Methods: Rats were fed a standard diet, a diet with a high content of valine, leucine, and isoleucine (HVLID), or a high content of leucine (HLD) for 2 months. Half of the animals in each group were sacrificed in the fed state on the last day, and the other half were sacrificed after overnight fast. Protein synthesis was assessed using the flooding dose method (L-[3,4,5-3 H]phenylalanine), proteolysis on the basis of chymotrypsin-like activity (CHTLA) of proteasome and cathepsin B and L activities. Results: Chronic intake of HVLID or HLD enhanced plasma levels of urea, alanine and glutamine. HVLID also increased levels of all three BCAA and branched-chain keto acids (BCKA), HLD increased leucine, ketoisocaproate and alanine aminotransferase and decreased valine, ketovaline, isoleucine, ketoisoleucine, and LDL cholesterol. Tissue weight and protein content were lower in extensor digitorum longus muscles in the HLD group and higher in kidneys in the HVLID and HLD groups. Muscle protein synthesis in postprandial state was higher in the HVLID group, and CHTLA was lower in muscles of the HVLID and HLD groups compared to controls. Overnight starvation enhanced alanine aminotransferase activity in muscles, and decreased protein synthesis in gastrocnemius (in HVLID group) and extensor digitorum longus (in HLD group) muscles more than in controls. Effect of HVLID and HLD on CHTLA in muscles in postabsorptive state was insignificant. The results failed to demonstrate positive effects of the chronic consumption of a BCAA-enriched diet on protein balance in skeletal muscle and indicate rather negative effects from a leucine-enriched diet. The primary effects of both diets are an activated catabolism of BCAAs, which leads to an enhanced production of BCKA, alanine and glutamine and their utilization in visceral tissues and an impaired protein synthesis in postabsorptive state, particularly in fast-twitch (white) muscles.

Hyperammonemia is considered to be the main cause of decreased levels of the branched-chain amino acids (BCAA), valine, leucine, and isoleucine, in liver cirrhosis. In this study we investigated whether the decrease in BCAA is caused by the direct effect of ammonia on BCAA metabolism and the effect of ammonia on BCAA and protein metabolism in different types of skeletal muscle. M. soleus (SOL, slow-twitch, red muscle) and m. extensor digitorum longus (EDL, fast-twitch, white muscle) of white rat were isolated and incubated in a medium with or without 500 lM ammonia. We measured the exchange of amino acids between the muscle and the medium, amino acid concentrations in the muscle, release of branched-chain keto acids (BCKA), leucine oxidation, total and myofibrillar proteolysis, and protein synthesis. Hyperammonemia inhibited the BCAA release (81% in SOL and 60% in EDL vs. controls), increased the release of BCKA (133% in SOL and 161% in EDL vs. controls) and glutamine (138% in SOL and 145% in EDL vs. controls), and increased the leucine oxidation in EDL (174% of controls). Ammonia also induced a significant increase in glutamine concentration in skeletal muscle. The effect of ammonia on intracellular BCAA concentration, protein synthesis and on total and myofibrillar proteolysis was insignificant. The data indicates that hyperammonemia directly affects the BCAA metabolism in skeletal muscle which results in decreased levels of BCAA in the extracellular fluid. The effect is associated with activated synthesis of glutamine, increased BCAA oxidation, decreased release of BCAA, and enhanced release of BCKA. These metabolic changes are not directly associated with marked changes in protein turnover. The effect of ammonia is more pronounced in muscles with high content of white fibres.

Extreme climate events are being recognized as important factors in the effects on crop growth and yield. Increased climatic variability leads to more frequent extreme conditions which may result in crops being exposed to more than one extreme event within a growing season. The aim of this study was to examine the implications of different drought treatments on the protein fractions in grains of winter wheat using 1 H nuclear magnetic resonance spectroscopy followed by chemometric analysis. Triticum aestivum L. cv. Vinjett was studied in a semi-field experiment and subjected to drought episodes either at terminal spikelet, during grain-filling or at both stages. Principal component trajectories of the total protein content and the protein fractions of flour as well as the 1 H NMR spectra of single wheat kernels, wheat flour, and wheat methanol extracts were analysed to elucidate the metabolic development during grain-filling. The results from both the 1 H NMR spectra of methanol extracts and the 1 H HR-MAS NMR of single kernels showed that a single drought event during the generative stage had as strong an influence on protein metabolism as two consecutive events of drought. By contrast, a drought event at the vegetative growth stage had little effect on the parameters investigated. For the first time, 1 H HR-MAS NMR spectra of grains taken during grain-filling were analysed by an advanced multiway model. In addition to the results from the chemical protein analysis and the 1 H HR-MAS NMR spectra of single kernels indicating that protein metabolism is influenced by multiple drought events, the 1 H NMR spectra of the methanol extracts of flour from mature grains revealed that the amount of fumaric acid is particularly sensitive to water deficits.