Na+/K+-ATPase

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32-D48 post-hatch, 15-25 mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87-D100 post-hatch, 38-48 mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, suggest that in SW-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydration in SW, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies.

Introduction: Since diabetic cardiomyopathy is associated with metabolic abnormalites and subcellular Ca 2+-handling defects, this study examined the effects of metabolic therapy with propionyl L-carnitine (PPLC) in modifying diabetes induced changes in cardiac sarcolemma (SL) Ca 2+-transport. Methods: Three days after inducing diabetes by injecting 65 mg/kg streptozotocin, rats were treated with or without PPLC (100 mg/kg; daily) for 8 weeks. These animals were assessed hemodynamically for cardiac function and the activities of some Ca 2+-transport systems were determined in cardiac SL preparations. Results: Improvement of cardiac function in diabetic animals by PPLC was associated with lowering of plasma lipids. Depressions in SL Na +-K + ATPase and Na +-Ca 2+ exchange activities in diabetic herats were partially attenuated by PPLC treatment. Maximal enzyme activities (V max values) for control, diabetes and PPLC-treated preparations for Na +-K + ATPase were 33.61, 18.46 and 27.64 (μmol Pi/mg/hr) whereas maximal Ca 2+-accumulation activities (B max values) for Na +-Ca 2+ exchange were 9.60, 5.09 and 7.65 μΜ Ca 2+ , respectively. Although both ATP-dependent Ca 2+-uptake and Ca 2+stimulated ATPase were depressed in diabetic SL, treatment with PPLC did not show any improvement in these activities. Alterations in different biomarkers of oxidative stress in diabetic heart were attenuated by PPLC treatment. Conclusions: These results indicate that alterations in SL Na +-K + ATPase and Na +-Ca 2+ exchange activities in diabetic heart may be attenuated by reduction in the development of oxidative stress by PPLC. It is suggested that modifictaion of SL defects by metabolic therapy with PPLC may contribute in reducing the occurence of intracellular Ca 2+-overload and improving cardiac function in diabetic cardiomyopathy.

The sodium pump or Na,K-ATPase was discovered in 1957. In view of the complexity of the system, its mechanism and roles are still not fully understood. The system is often ignored or confused with channels and other transporters. It is also poorly known that the sodium pump is the pharmacological receptor for cardioactive steroids from plants (ouabain, digoxin, convallotoxin, etc.) and from the toad (bufotoxins), and for the powerful palytoxin from the coral palythoa toxica.
The current book presents a summary of most aspects of the sodium pump, going from its discovery to the properties of the molecule, its isolation and reconstitution into artificial membranes, to the roles in the cell and in the organism, and to its alteration by environmental stress and disease, including radiation damage, a particular problem during space flight.
The book is designed to be a guide to the status of knowledge on the sodium pump/Na,K-ATPase in the 20th century, giving easy access to all relevant topics and to the corresponding literature. Over 1200 references are cited. The topics are illustrated with simple schemes and drawings, and some aspects are illustrated by original data of the author's laboratory, who had started her PhD work on Na.K-ATPase in 1969 in the Department of Pharmacology, University of Geneva, Switzerland. Each chapter can be singled out and read separately since it contains a full description of the topic. Simple drawings, sketches and schemes facilitate the understanding of complex topics.
Hence, the book presents a "time-saver": complex knowledge on the sodium pump is presented in condensed form in a single volume. However, a single book cannot be exhaustive on such a large topic, and some aspects were not reviewed in detail, in particular the precise structure of the molecular structure and the modulation of the system by hormones; such topics can be read in reviews or in specialized books.
On the other hand, the strength of this book lies in its historical dimension, since virtually the whole pioneering work performed in the 20th century is reviewed, with the advantage, that the author had the occasion to discuss personally about the sodium pump or to perform collaborations with some prominent investigators in the field, i.e. to be able to share firsthand knowledge. Part of the research performed by the author’s research group  on the isolation and reconstitution of the sodium pump in artificial membranes (liposomes) is also shown in this book.
In sum, the present book presents a unique occasion to gain rapidly sound knowledge on the sodium pump (Na,K-ATPase), from its discovery to the Nobel Prize of Jens Chistian Skou for his work on Na,K-ATPase in 1997, and two years beyond.

The current study was conducted at agro-eycosystem of Basra province during the period 2013-2014, to evaluate the diversity of spiders community. 24 species, 23 genera belong to 10 families was recorded, the most relative abundance was registered for family Lycosidae 0.80. the most divers month was November 2.88, the results of correlation revealed a negative correlation between number of spiders and wind speed, as well as air temperature degree, whereas the number of spiders correlated positively with rain quantity and relative humidity.

The aim of this study was to evaluate the effect of Biofield Energy Treated/Blessed Proprietary Test Formulation and Biofield Energy Treatment/Blessing per se on cardiac biomarkers in aorta homogenate on L-NAME and high fat diet (HFD)-induced cardiovascular disorders in Sprague Dawley rats. The functional aortic biomarkers such as inducible nitric oxide synthase (iNOS), angiotensin-II, C-reactive protein (CRP), cholesterol, troponin-1, and Na+/K+-ATPase were measured using standard ELISA assay. A test formulation was formulated including minerals (magnesium, zinc, copper, calcium, selenium, and iron), vitamins (ascorbic
acid, pyridoxine HCl, vitamin B9, cyanocobalamin, and cholecalciferol), Panax ginseng extract, β-carotene, and cannabidiol isolate. In this experiment, nine groups were assigned, in which four were preventive maintenance groups. The ingredients were used in this formulation divided into two parts; one was defined as the unblessed test formulation, while the other portion of the test formulation received Biofield Energy Healing Treatment/Blessing remotely for about 3 minutes by a renowned Biofield Energy Healer, Mr. Mahendra Kumar Trivedi. Among nine groups, three groups of animals were also received Blessing per se (at day -15). The results showed that the level of iNOS was significantly (p≤0.001) reduced by 32.4%, 27.8%, and 19.8% in the G5 (L-NAME + HFD + the Biofield Energy Treated test formulation), G6 (L-NAME + HFD + Biofield Energy Treatment per se to animals from day -15), and G7 (L-NAME + HFD + the Biofield Energy Treated test formulation from day -15) groups, respectively as compared to the disease control group (G2). Moreover, the level of angiotensin-II was significantly decreased by 33.6%, 47.2% (p≤0.001), 27.9%, 25.4%, and 22.3% in the G5, G6, G7, G8 (L-NAME + HFD + Biofield Energy Treatment per se plus the Biofield Energy Treated test formulation from day -15), and G9 (L-NAME + HFD + Biofield Energy Treatment per se animals plus the untreated test formulation) groups, respectively, as compared to the G2 group. The level of CRP was decreased by 26.1%, 25.7%, 15.8%, and 16.6% in the G5, G6, G7, and G9 groups, respectively as compared to the G2 group. Besides, the level of cholesterol was significantly (p≤0.001) decreased by 62.4%, 54.5%, 52%, 46.2%, and 64.1% in the G5, G6, G7, G8, and G9 groups, respectively as compared to the G2 group. The level of troponin-1 was significantly (p≤0.001) decreased by 42.8%, 42.5%, 36.7%, 28.9%, and 21.2% in the G5, G6, G7, G8, and G9 groups, respectively as compared to the G2 group. The level of Na+/K+-ATPase was decreased by 14.8% in the G8 group as compared to the G4 group. Overall, the data suggested significance improvement of vital functional aortic biomarkers of the Biofield Energy Treated test formulation and Biofield Energy Treatment per se along with preventive measure on the animal with respect to various pathological conditions that might be beneficial various types of cardiovascular disorders. Therefore, the results showed the significant slowdown the cardiovascular diseases and its complications in the preventive Biofield Energy Treatment group per se and/or Biofield Energy Treated/Blessed Test formulation groups (viz. G6, G7, G8, and G9) as compared to the disease control group.

In 1997 Jens Christian Skou, Aarhus University, Danemark, won the Nobel Prize for hist work on Na,K-ATPase. Due to reconstitution techniques, consisting in the insertion of purified Na,K-ATPase into artificial membranes, the Na,K-ATPase system was shown to be analogous to the sodium pump described previously by physiologists. This brochure describes the work of JC Skou and contributors, from around the world, among them Beatrice M Anner from the University of Geneva, Switzerland.

There is a need to control Spodoptera frugiperda with new pesticides that have unusual modes of action. Spodoptera frugiperda initial larval instars can spin silk threads which would be the target of synthetic 2-Cyano-N-(3-(N-(thiazol-2-yl) sulfamoyl) phenyl) acetamide. The toxicity of synthetic derivatives (Ar1, Ar2, and Ar3) was tested against 1st and 2nd larval instars. Besides, the silk spinning ratio was examined after treatments with LC50s of certain derivatives, and different shapes of produced silk were detected in comparison with the control by SEM. In addition, malformation percentages of initial instars and latent effects were recorded. Biochemical experiments were done upon treatments with LC50s of derivatives. Results showed that Ar1 was the most effective derivative against S.frugiperda 1st and 2nd larval instars with LC50 values of 781.65 and 904.39 µLL¯¹, respectively. Spinning ratios were 6.67,13.33,26.67 and 93.33 % for Ar1, Ar2, Ar3, and control, respectively, and differences in silk strands were detected morphologically upon potent interaction with the induced treatments. Results were explained upon more biochemical analysis which showed that Ar1 recorded the highest values of total protein and total lipids, while it was the lowest in the case of enzymes such as protease, amylase, and Na+K+ATPase. It could be concluded that synthetic 2-Cyano-N-(3-(N-(thiazol-2-yl) sulfamoyl) phenyl) acetamide derivatives would be used as promising insecticides and anti-spinning silk threads compounds effectively against Spodoptera frugiperda larvae with registered high mortality percentages.

Literature on the mechanisms of magnesium transport through fish intestine is scarce. Indirect evidence for a net magnesium transport via the intestinal tract of fish has been established by dietary experiments (e.g. with carp Cyprinus carpio L. and nile perch Oreochromis niloticus Peters), showing that dietary magnesium is essential for the growth of these fish (Ogino and Chiou, 1976; Dabrowska et al. 1989). Nakamura and Hirano (1986) suggested 'solvent drag' as a mechanism for net magnesium transport in eel Anguilla japonica intestine. For mammals, the reports on this topic are equivocal. In the small intestine of the rat, diffusion (Ross, 1962; Aldor and Moore, 1970; O'Donnell and Smith, 1973) as well as solvent drag (Behar, 1974) were reported to underlie magnesium absorption, although the possibility of an active transport component was kept open by these authors. For the intestine of guinea pig, active transport of magnesium was demonstrated (Ross and Care, 1962; Partridge et al. 1987). This communication deals with magnesium transport across stripped intestinal epithelium of freshwater tilapia and its possible mechanisms. Male tilapia {Oreochromis mossambicus Peters), weighing around 150g, were obtained from laboratory stock and kept in Amsterdam municipal tap water with a magnesium concentration of about 0.25 mmol I" 1 and at a temperature of 28±2°C. The photoperiod was automatically controlled (12 h light: 12 h dark) and the fish were fed once daily with tropical fish food (magnesium content 31 mmol g" 1 ; Tetramin). Fish were sacrificed by spinal transection just behind the gills. The intestine was cut free behind the stomach, transferred to saline and flushed with the same solution. Next, the intestine was cut lengthwise and the mucosa stripped of its underlying muscular layers as described by Albus et ,al. (1979). All experiments were performed at room temperature.

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32-D48 post-hatch, 15-25 mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87-D100 post-hatch, 38-48 mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, suggest that in SW-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydration in SW, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies.

The European sea bass, Dicentrarchus labrax, being a member of the family Morenidae is a remarkable euryhaline species capable of tolerating both hypersaline and freshwater (FW) environments (1,2). It has been ... Turk J Vet Anim Sci 26 (2002) 993-1001 © TÜB‹TAK

This study investigated the dietary component and morphology of the digestive tract of Anguilla marmorata during its yellow stages (non-migrants). A total of 127 samples, ranging in total length from 17-108 cm and weight from 10-3200 g were collected from Thua Thien Hue, Vietnam. The structure of the gastrointestinal tract indicated that Anguilla marmorata has the typical characters of carnivorous fish such as a wide mouth, small teeth in bands; free tongue; short esophagus, stomach, and intestines made up of folds. The mouth size of Anguilla marmorata ranged from 1.81-6.6 cm and it increased with the body weight of fish. Anguilla marmorata is an animal-eating species with an RLG (relative length of the gut) ranging from 0.34 to 0.41 (RLG <1). Crustacea is the preferred food of eels with the highest proportion of the number, weight, and frequency of crustaceans in the gastrointestinal tract with 65%, 64%, and 80%, respectively. Crustacea was also the most important food of Anguilla marmorata in the wild with the index of relative importance (IRI%)=79%. Correlation equation between length (L=17-108 cm) and weight (W=10-3200 g) of Anguilla marmorata is L=9.948W 0.0622 with correlation coefficient R 2 =0.93. Our report provides new dietary information about A. marmorata that is useful in nutrition planning and aquaculture potential.

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32-D48 post-hatch, 15-25 mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87-D100 post-hatch, 38-48 mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, suggest that in SW-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydration in SW, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies.

Siberian sturgeon farming is important because it provides an alternative source of caviar and meat, but also for the conservation of the endangered natural stocks. Farmed fish is continuously subjected to stress factors, of which, water temperature is considered a major one (Schram et al., 2006). It has been demonstrated that physiological stress may have serious negative consequences on growth (Wendelaar Bonga, 1997) and that fish larvae appear less tolerant than adults to temperature variations (Stefanovich et al., 2016). The present study aims at investigating the stress response and development in precocious stages of siberian sturgeon when subjected to different rearing temperatures, by analysing ontogeny, growth and stress response of yolk-sac larvae. This study was approved by the Ethic Committee of the University of Milan (OPBA_20_2016). Fertilized Siberian sturgeon eggs were reared at 16°C, 19°C and 22°C until complete yolk-sac absorption. Sampling timepoints were: hatchin...

The histological structure, histochemical features, and enzymatic activity of the digestive tract of juvenile Pacific seahorse (Hippocampus ingens) are described to provide information during the cultivation of this species. Serial histological sections were stained with either hematoxylin-eosin, alcian blue-PAS, toluidine blue, Sudan black, Masson&#39;s trichome, and ninhydrin-Schiff to describe the general features and the presence of glycogen, mucopolysaccharides, lipids, muscle layers, and proteins, respectively. The enterocytes height and the mucosal villi height in the esophagus and intestines were measured. Additionally, the digestive enzymes trypsin, chymotrypsin, lipase, amylase, aminopeptidase, acid phosphatase, and alkaline phosphatase activities were recorded. The esophagus showed two distinctive regions, the anterior with numerous mucous cells secreting acid mucins and the posterior with longitudinal folds and no mucous cells. The intestine was differentiated into three...

In this study, development of the digestive tract of the Black Sea Trout (Salmo trutta labrax PALLAS, 1811) which is endemic and also endangered species in their natural habitat was identified in early larval stages. For this reason, fish larvae breeding in fresh water recirculating aquaculture system (RAS) were examined by histologically from hatching to fish larvae consumed their yolk sac. Finally, the digestive system of Black Sea trout which is endemic and also endangered species in their natural habitat was determined.

Several aspects of the biology of European eel (Anguilla anguilla) larvae are still unknown; particularly, information about their functional development and feeding is sparse. In the present study, we histologically characterize the digestive system of wild caught specimens of European eel leptocephalus larvae. The aim was to provide more understanding about how food may be ingested and mechanically processed in the leptocephalus larvae, and to discuss this in the context of its hypothesized feeding strategy. Larvae were caught in the Sargasso Sea during the “Danish Eel Expedition 2014” with the Danish research vessel Dana. The larval sizes ranged from 7.0 to 23.3 mm standard length (SL) at catch. We found that the mouth/pharynx, especially the anterior esophagus, was surrounded by a multi-layered striated muscle tissue and that the epithelium in the mouth/pharynx had a rough filamentous surface, followed by epithelial columnar cells with multiple cilia in the anterior esophagus. T...

Bilal Ahmad Paray, Haniffa M.A, Mehraj Ud Din War, Mohammad K. Al-Sadoon, Yong-Ha Park & Irfan A. Rather Centre for Aquaculture Research and Extension, St. Xavier’s College (Autonomous) Palayamkottai, 627-002, India PG and Research Department of Zoology, The New College, Peters Road, Royapettah, Chennai, Tamil Nadu 600-014, India Zoology Department, College of Science, King Saud University, PO Box 2455, Riyadh 11451, Saudi Arabia Department of Applied Microbiology and Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk 712-749, South Korea

The histological structure, histochemical features, and enzymatic activity of the digestive tract of juvenile Pacific seahorse (Hippocampus ingens) are described to provide information during the cultivation of this species. Serial histological sections were stained with either hematoxylin-eosin, alcian blue-PAS, toluidine blue, Sudan black, Masson&#39;s trichome, and ninhydrin-Schiff to describe the general features and the presence of glycogen, mucopolysaccharides, lipids, muscle layers, and proteins, respectively. The enterocytes height and the mucosal villi height in the esophagus and intestines were measured. Additionally, the digestive enzymes trypsin, chymotrypsin, lipase, amylase, aminopeptidase, acid phosphatase, and alkaline phosphatase activities were recorded. The esophagus showed two distinctive regions, the anterior with numerous mucous cells secreting acid mucins and the posterior with longitudinal folds and no mucous cells. The intestine was differentiated into three...

This study investigated the dietary component and morphology of the digestive tract of Anguilla marmorata during its yellow stages (non-migrants). A total of 127 samples, ranging in total length from 17-108 cm and weight from 10-3200 g were collected from Thua Thien Hue, Vietnam. The structure of the gastrointestinal tract indicated that Anguilla marmorata has the typical characters of carnivorous fish such as a wide mouth, small teeth in bands; free tongue; short esophagus, stomach, and intestines made up of folds. The mouth size of Anguilla marmorata ranged from 1.81-6.6 cm and it increased with the body weight of fish. Anguilla marmorata is an animal-eating species with an RLG (relative length of the gut) ranging from 0.34 to 0.41 (RLG <1). Crustacea is the preferred food of eels with the highest proportion of the number, weight, and frequency of crustaceans in the gastrointestinal tract with 65%, 64%, and 80%, respectively. Crustacea was also the most important food of Anguilla marmorata in the wild with the index of relative importance (IRI%)=79%. Correlation equation between length (L=17-108 cm) and weight (W=10-3200 g) of Anguilla marmorata is L=9.948W 0.0622 with correlation coefficient R 2 =0.93. Our report provides new dietary information about A. marmorata that is useful in nutrition planning and aquaculture potential.

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32-D48 post-hatch, 15-25 mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87-D100 post-hatch, 38-48 mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, suggest that in SW-acclimated fish, the imbibed water is absorbed via AQP1a through the digestive tract, particularly the intestine and the rectum. In addition, AQP1a may play a role in water reabsorption in the kidney. These mechanisms compensate dehydration in SW, and they contribute to the adaptation of juveniles to salinity changes during sea-lagoon migrations. These results contribute to the interpretation of the adaptation of populations to habitats where salinity varies.

The successful establishment of a species in a given habitat depends on the ability of each of its developing stages to adapt to the environment. In order to understand this process we have studied the adaptation of a euryhaline fish, the sea-bass Dicentrarchus labrax, to various salinities during its ontogeny. The expression and localization of Aquaporin 1a (AQP1a) mRNA and protein were determined in different osmoregulatory tissues. In larvae, the sites of AQP1a expression are variable and they shift according to age, implying functional changes. In juveniles after metamorphosis (D32–D48 post-hatch, 15–25mm) and in pre-adults, an increase in AQP1a transcript abundance was noted in the digestive tract, and the AQP1a location was observed in the intestine. In juveniles (D87–D100 post-hatch, 38–48mm), the transcript levels of AQP1a in the digestive tract and in the kidney were higher in sea water (SW) than at lower salinity. These observations, in agreement with existing models, sugg...

The ontogeny of osmoregulation was examined in the branchial cavity of embryonic and early post-embryonic stages of the crayfish Astacus leptodactylus maintained in freshwater, at the sub-cellular level through the detection of the sodium–potassium adenosine triphosphatase (Na+,K+-ATPase). The embryonic rate of development was calculated according to the eye index (EI) which was 430–450 μm at hatching. The distribution of the enzyme was identified by immunofluorescence microscopy using a monoclonal antibody IgGα5 raised against the avian α-subunit of the Na+,K+-ATPase. Immunoreactivity staining, indicating the presence of Na+, K+-ATPase appeared in the gills of late embryos (EI≥400 μm), i.e. a few days before hatching time, and steadily increased throughout the late embryonic and early post-embryonic development. The appearance of the enzyme correlates with the ability to osmoregulate which also occurs late in the embryonic development at EI 410–420 μm and with tissue differentiatio...

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Despite the relevance of primary cell culture from the gill tissue, there are no reports on the branchial cell lines of the striped bass Morone saxatilis (Walbaum, 1792). The importance of establishing cell lines from M. saxatilis branchial tissue represents an alternative to studying infective physiological and biochemical processes, which may facilitate research without compromising valuable live animals. Branchial tissue explants were cultured in 2 × Leibovitz L-15 (pH 7.2 ± 2) medium supplemented with 20 % foetal bovine serum (FBS) and 2 × antibiotic-antimycotic adjusted to 578 mOsm.kg-1. Primary cell cultures obtained showed excellent cell adhesion and proliferation. The cell monolayer consisted of epithelial cells, and the culture was maintained for approximately 30 days. This is the first report describing primary branchial cell line culture from striped bass.

The development of osmoregulatory and gas exchange organs was studied in larval yellowfin tuna (Thunnus albacares) from 2 to 25 days post-hatching (2.9-24.5 mm standard length, SL). Cutaneous and branchial ionocytes were identified using Na + /K +-ATPase immunostaining and scanning electron microscopy. Cutaneous ionocyte abundance significantly increased with SL, but a reduction in ionocyte size and density resulted in a significant decrease in relative ionocyte area. Cutaneous ionocytes in preflexion larvae had a wide apical opening with extended microvilli; however, microvilli retracted into an api-cal pit from flexion onward. Lamellae in the gill and pseudobranch were first detected ~ 3.3 mm SL. Ionocytes were always present on the gill arch, first appeared in the filaments and lamellae of the pseudobranch at 3.4 mm SL, and later in gill filaments at 4.2 mm SL, but were never observed in the gill lamellae. Unlike the cutaneous ionocytes, gill and pseudobranch ionocytes had a wide apical opening with extended microvilli throughout larval development. The interlamellar fusion, a specialized gill structure binding the lamellae of ram-ventilating fish, began forming by ~ 24.5 mm SL and contained iono-cytes, a localization never before reported. Ionocytes were retained on the lamellar fusions and also found on the filament fusions of larger sub-adult yellowfin tuna; however, sub-adult gill ionocytes had apical pits. These results indicate a shift in gas exchange and NaCl secretion from the skin to branchial organs around the flexion stage, and reveal novel aspects of ionocyte localization and morphology in ram-ventilating fishes.

This paper discusses current views of ion transport in cardiac cell membrane and how the views have changed from classical membrane models. Data from patch clamp experiments is making it possible to construct state-diagram models for passive channels. Protein-mediated transport such as pumps and exchangers a re now known to be essential in the description of cardiac cells. Ion concentrations inside and outside the cell are known to vary with time and some of the variations contribute substantially to ion regulation. Present models of ion transport in cardiac cells are thus much more complex than classical models and require significantly more computation to find solutions. Descriptions of currents in terms of activation a nd inactivation variables have been replaced by calculations of net and unidirectional fluxes through reactions described by state diagrams.

The Na,K-stimulated ATPase is inhibited by extra-cellular cardiac glycosides, which bind to the enzyme's (Y subunit. We used a monoclonal antibody, VG4, as a probe of the extracellular surface. The antibody was specific for Na,K-ATPase and bound to intact cells. The epitope was mapped to the first extracellular loop (Hl-HZ) of a, using a combination of techniques including trypsinolysis, N-terminal sequence of a fragment containing the determinant, and analysis of the effects of species-specific sequence differences. The antibody inhibited Na,K-ATPase activity under certain circumstances, indicating that the H1-HZ loop participates in conformational changes that are transmitted to the active site. Mutations in the H1-HZ loop have been shown by others to affect ouabain affinity. Ouabain and the antibody acted synergistically to inhibit the enzyme, which seemingly supported the hypothesis that the H1-HZ loop is an essential part of the cardiac glycoside binding site. Direct measurements of the binding of [3H]ouabain, however, indicated that VG4 enhanced rather than inhibited binding, presumably by promoting favorable conformation changes. The data suggest the possibility that the cardiac gly-coside binding site may be intramembrane rather than extracellular. Na,K-ATPase' catalyzes the active transport of Na+ and K' across the plasma membrane. The enzyme is specifically inhibited by cardiac glycosides, and early work established unequivocally that the inhibitors act from the outside surface of the cell (1). The enzyme comprises two subunits: a 112-kDa catalytic subunit, a, which has the binding site for ATP; and a 32-kDa glycoprotein subunit, 8, which is required for assembly and for targeting to the plasma membrane. There is much evidence that the a subunit spans the membrane multiple times, exposing the majority of its mass at the intracel-lular surface, whereas the p subunit spans the membrane only once, exposing the majority of its mass at the extracellular surface (2). It is a widely held premise that the cardiac

The anatomy and the histology of the digestive tract of young and adult sea-bream is described from studies using light and scanning electron microscopy. The dentition in the juvenile (25-30 mm long) comprises all canine-like teeth. to which plate teeth and transition elements are added in the adult.

In this study, development of the digestive tract of the Black Sea Trout (Salmo trutta labrax PALLAS, 1811) which is endemic and also endangered species in their natural habitat was identified in early larval stages. For this reason, fish larvae breeding in fresh water recirculating aquaculture system (RAS) were examined by histologically from hatching to fish larvae consumed their yolk sac. Finally, the digestive system of Black Sea trout which is endemic and also endangered species in their natural habitat was determined.

The digestive tract of Takifugu rubripes during early life stages was studied with light microscopy. At the beginning of hatching, the digestive tract is represented by a simple and undifferentiated straight tube and does not communicate with the exterior, as the mouth and anus are not open yet. At 2d after hatching, a constriction between intestine and rectum that will become the intestino-rectal valve is visible. During the endogenous feeding phase, the yolk sac is resorbed and the digestive tract becomes functional and differentiated. The liver and pancreas also become apparent at this time. At onset of exogenous feeding (3 d after hatching), yolk sac resesves are not completely depleted, suggesting a period of mixed nutrition. The digestive tract differentiates fully into b.uccopharynx, esophagus, stomach, intestine and rectum. At 9 d after hatching, the yolk sac reserves are completely depleted. The most noticeable events occurring from 5 to 17 d after hatching are the transformation of the epithelia type, the differentiation of the pneumatic sac, the epithelial cell, gut convolution, mucosal fold increase, and the growth of liver and pancreas. From 18 to 27 d after hatching, the numbers of intestine folds and mucus cells increase progressively. From then on, morphological changes of digestive features are almost completed. At 27 d after hatching, the morphology and function of digestive system are similar to that of the adult.

We present here a Hopf bifurcation that has the shape of an « e » (we provide a figure beneath), studied with more details in Dieterlen 1981. The 2 variables are the reaction temperature and delta(x), the difference between outside and inside a living cell substrate concentrations. When one increases the abscissa parameter (energy input, ATP), 2 of the 3 steady states disappear, and we are left with the " down " steady state branch. It was devised originally as a model of the Na +-K + pump in special living or artificial cells, but should be considered as a stirred thermal reactor with a highly non-linear relation between the substrate diffusion and the energy input or reaction rate. We present the equations for the model without calculations, and the " e " shaped figure for delta(x), function of the diffusion coefficient. The stability analysis is not presented, due to its length. It can also be found in Dieterlen 1981 a study of limit cycles for this sodium pump.

The osmoregulatory system of two groups of young Persian sturgeon Acipenser persicus (BORODIN) was studied by means of monitoring changes in blood serum and urine osmolarity level after the transfer of young fish from fresh (Control) to sea water of 10.5 and 12.5 salinity (Experiment), and by means of examining ultrastructural changes in the gill chloride cells during the adaptation of fishes to sea water. The 1st group included fish of mean weight 3.6 g and mean length 10.3 cm; the 2nd group included fish of mean weight 206.6 g and mean length 43.8 cm. An increase in osmoregulatory ability and morpho-functional development of chloride cells during the growth of fish are observed.

Freshwater acclimatized spotted scat (Scatophagus argus) adults were adapted to 5, 10, 20 or 30 g/l seawater and observed for morphometric changes in gill and kidney histology at time points 1, 2, 10, 15 and 30 days. The overall histomorphological changes displayed by gill and kidney suggest two different phases of successful saltwater acclimation: an adaptive phase with adjustments in the abundance of gill chloride cells and renal collecting tubules, the diameter of glomerulus and collecting tubules, and the thickness of the muscular tissue of the collecting tubules; this gives way to a period with no further significant morphometric modifications.

Glass eels (Anguilla anguillu, L. 1758) caught during ascent at the mouth of the RiverTiber were kept in aquaria with freshwater and full strength salinity (35 %) for four months. Morphological features of glass eels at capture and after four months of experimental rearin are described. The structure of the gut, an important osmoregulatory organ, observed in $ass ee?s in seawater experimental rearing suggests that they undergo an irreversible process of a aptation to freshwater, despite the fact of survival in seawater. U.S. Copyright Clearance Center Code Statement: 0175-8659/93/0901-0074s 02.50/0 BERNDT, O., 1938: Mor hologie und Histolo ie des Rumpfdannes von Anguilla fluviatilis und die Veranderungen desseken irn Individuahykks. Zool. Fb. (Anat) 64: 437-482. BERTIN, L., 1956: Eels, a biological study. London, Cleaver Hume Press Ltd., 192 pp. BOETIUS, J., 1976: Elvers, Anguilla anguilla and An nilla rostruta, from two Danish localities. Size, BOEUP, G., 1987: Bases hysiologiques de la salmonicolture: osmorkgulation et adaptation 1 I'eau de CANTRELLE, I., 1984: Les populations de civelles d'Anguilla anguilkz L. en migration dans I'estuaire de body weight, developmental stage and number o r ? vertebrae related to time of ascent. Medd. Dan. Fiskog Havunders 7: 199-219. mer. La pisciculture &nCaise 87: 28-40. la Gironde. Vie Milieu 34(2/3): 109-116. Anguilla japonicu, during adaptation to sea water. CellTiss. Res. 192: 25-38. 187-199. 33-40.

The ontogeny of differentiated osmoregulatory epithelia in the branchial chamber (gills, branchiostegite, pleura, epipodite) was studied by transmission electron microscopy throughout the postembryonic development of Penaeus japonicus. These epithelia are characterized by typical cytological features, including apical microvilli and numerous basal infoldings associated with mitochondria. Differentiated osmoregulatory structures are not observed in the early larval stages: nauplii and zoea 1. In the next larval stages, zoeas and mysis, gills and epipodites are developed as buds only, but osmoregulatory epithelia are observed in the branchiostegites and pleurae. The differentiated structures of the branchiostegites and pleurae are still present in postlarvae but disappear in juveniles and adults. Gills and epipodites develop progressively in the postlarval stages, with early differentiation of osmoregulatory epithelia in the epipodites. In juveniles and adults, the gill epithelium is poorly differentiated; in contrast, abundant differentiated osmoregulatory structures are observed in the epipodites.

The localization of Na + ,K + -ATPase in epithelia of the organs of the branchial cavity of Homarus gammarus exposed to seawater and dilute seawater was examined by immunofluorescence microscopy and immunogold electron microscopy with a monoclonal antibody IgGα 5 raised against the avian α-subunit of the Na + ,K + -ATPase. In juveniles held in seawater, fluorescent staining was observed only in the epithelial cells of epipodites. In juveniles held in dilute seawater, heavier immunoreactivity was observed in the epithelial cells of epipodites, and positive immunostaining was also observed along the inner-side epithelial layer of the branchiostegites. No fluorescent staining was observed in the gill epithelia. At the ultrastructural level, the Na + ,K + -ATPase was localized in the basolateral infolding systems of the epipodite and inner-side branchiostegite epithelia of juveniles held in dilute seawater, mostly along the basal lamina. The expression of Na + ,K + -ATPase therefore differs within tissues of the branchial cavity and according to the external salinity. These and previous ultrastructural observations suggest that the epipodites, and to a lesser extent the inner-side epithelium of the branchiostegites, are involved in the slight hyper-regulation displayed by lobsters at low salinity. Enhanced Na + ,K + -AT-Pase activity and de novo synthesis of Na + ,K + -ATPase within the epipodite and branchiostegite epithelia may be key points enabling lobsters to adapt to low salinity environments.

Atlantic red porgy, Pagrus pagrus, is an important reef fish species in the Mediterranean and the snapper-grouper complex off the southeastern United States. Red porgy is a viable candidate for aquaculture with high market value and the ability to spawn freely in captivity. The objective of this study was to examine the combined effects of temperature and salinity on eggs, yolk-sac larvae, and early feeding-stage larvae of red porgy to day 16 posthatching (d16ph). To determine the optimal temperature and salinity conditions for culture, embryos were reared under four temperatures (17, 19, 21, and 23°C) and two salinities (24 and 34 g/L) in a 4 × 2 factorial design. Significant effects of temperature and salinity on growth (notochord length, wet and dry weight), survival, whole body osmolality, and expression of Na + /K + ATPase were observed with minimal interactive effects. Under both salinities, growth increased with increasing temperature. On d16ph, wet weights at 21 and 23°C (2.03 and 2.91 mg, respectively) were significantly higher than at 17 and 19°C (0.20 and 0.69 mg). Salinity had no effect on growth at any temperature, but had a significant effect on survival to d16ph, with greater survival at 24 g/L (18.4%) than at 34 g/L (6.77%). Salinity significantly affected whole body osmolality on d2ph and d11ph, with 24 g/L having lower whole body osmolality than 34 g/L on both days. Temperature significantly affected whole body osmolality on d6ph, with no clear trends and on d17ph, with 17°C (534 mOsm/kg) higher than all the higher temperatures (396-411 mOsm/kg). After increasing each tank to 44 g/L to create a sublethal salinity challenge on d16ph, larvae from 34 g/L treatments did not show an increase in levels of Na + /K + ATPase mRNA after 24 or 48 h post transfer. However, fish in the 24 g/L treatments showed a significant increase in expression of Na + /K + ATPase mRNA after 24 h followed by a decrease after 48 h. Within the ranges tested, a temperature of 23°C and a salinity of 24 g/L appear to be optimal for culture of red porgy embryos, yolk-sac, and first-feeding stage larvae to d16ph.

The aim of the study was to give an overview of the mechanism of inhibition of Na+/K+-ATPase and Mg2+-ATPase activity, the enzymes playing a key role in the active transport of monovalent cations (Na+ and K+) across the cell membrane, induced by the ions of some transition (Cu2+, Zn2+, Fe2+, Co2+) and heavy (Hg2+ i Cd2+) metals, ammonium decavanadate and noble metals complexes ([PtCl2DMSO2], [AuCl4](-), [PdCl4](2-), [PdCl(dien)](+), [PdCl(Me(4)dien)](+)). The extensive kinetic analysis was done in order to determine kinetic parameters and the mode of interaction of Na+/K+-ATPase and Mg2+-ATPase and the investigated compounds. In addition, the ability of sulphur-donor ligands (L-cysteine and glulathione), as well as EDTA, to prevent metal ions and complexes induced inhibition of Na+/K+-ATPase activity and to recover enzymatic activity was investigated Finally, development of highly sensitive and selective analytical tools on the basis of the immobilized enzyme is discussed in this pa...