Efectos de la aclimatización al cortisol y a la salinidad en el Na+/K+/2Cl–- cotransportador de expresión génica y en la actividad Na+, K+-ATPasa en las branquias de juveniles del Esturión de Persia

Na+, K+-ATPase activity and Na+/K+/2Cl–- cotransporter (NKCC) gene expression in the gills of Persian sturgeon, Acipenser persicus, fry (2-3 g, 3.30-8.12 cm total body length) in freshwater (control group), diluted Caspian Sea water (5 ppt) and after treatment with cortisol in freshwater were studied. Na+, K+-ATPase activity was lower in the 5 ppt-acclimated fish (1.07±0.05 _mol Pi/mg protein/h) than in the control fish (1.19±0.05 μmol Pi/mg protein/h) but this difference was not significant. nKCC gene expression in the 5 ppt-acclimated fish (1.6±0.07) was significantly higher than in the control fish (0.8±0.00). In the cortisol treated fish, Na+, K+-ATPase activity (1.91±0.05 μmol Pi/mg protein/h) and NKCC gene expression (3.2±0.1) were significantly higher than in the control group. our results show that Persian sturgeon fry (2-3 g) can tolerate 5 ppt salinity by changing their enzymatic content and activity, and that exogenous cortisol application can increase the osmoregulatory capacity of fry before release into brackish water and can reduce their mortality.Se estudió la actividad Na+, K+-ATPasa y el cotransportador de expresión génica (NKCC) Na+/K+/2Cl–- en las branquias de juveniles de esturión de Persia, Acipenser persicus, (2-3 g, 3.30-8.12 cm de longitud total) en agua dulce (grupo control), agua diluida del mar Caspio (5 ppt) y posterior tratamiento con cortisol en agua dulce. La actividad Na+, K+-ATPasa fue menor en los peces aclimatados en 5 ppt (1.07±0.05 μmol Pi/mg proteína/h) que en los peces (1.19±0.05 μmol Pi/mg proteína/h), pero esta diferencia no fue significativa. La expresión génica NKCC en peces desde 5 ppt de salinidad (1.6±0.07) fue significativamente más alta que en el grupo (0.8±0.00). en los peces tratados con cortisol la actividad Na+, K+-ATPasa (1.91±0.05 μmol P Pi/mg proteína/h) y la expresión génica NKCC (3.2±0.1) incrementaron significativamente en comparación con el grupo control. nuestros resultados mostraron que los juveniles de esturión de Persia (2-3 g) pueden tolerar 5 ppt de salinidad y esta capacidad se consiguió cambiando su contenido y actividad enzimática; -la aplicación de cortisol exógeno puede incrementar la capacidad osmoregulatoria de los juveniles antes de soltarlos a aguas salobres y puede reducir su mortalidad

Determination of fatty acids composition in Persian Gulf shrimp, Metapenaeus affinis

The aim of this work was to analyze the fatty acid profile in Persian Gulf shrimp, Metapenaeus affinis that is one of the edible and well-known shrimps and has suitable amount of fatty acids specific polyunsaturated fatty acids (PUFA). It has been reported that, a high dietary consumption of marine n-3 fatty acids may prevent the development of atherosclerosis and thrombosis. The fatty acids profile were analysed in the male and female shrimps. The maximum amount of saturated fatty acids (SFA) was 35.88 percent of total fatty acids in Bandar Abbas (St. A) samples. Highest monounsaturated fatty acids (MUFA) were 19.59% in station C and uppermost of PUFA was in Bushehr samples equal to 47.2 %. The figures of SFA showed significant difference between stations (p<0.05). MUFA hadn’t significantly different (p>0.05) and finally PUFA differed statistically only between station A and B. ω3 and ω9 in station A also had statistically differ with other stations and demonstrate that ω3 lower but ω9 higher than other stations. Difference in percentage of fatty acids among stations may consequence of consuming different nutrients by each group of shrimp

Effects of Cortisol on Gill Chloride Cells in Persian Sturgeon Acipenser persicus Fry

Objective: cortisol is the major corticosteroid in fish osmoregulation and Persian sturgeonis one of the endangered and economical species of the Caspian Sea sturgeons;this study is one of the first to investigate the effects of cortisol on one species of theAcipenserids species.Materials and Methods: Samples were fixed in Bouin’s solution, dehydrated, embeddedwith paraplast and subsequently sectioned. Immunohistochemical studies wereperformed by using IgGα5 and flourescin isothiocyanate conjugated (FITC) antibodiesthrough fluorescence light microscopy. Measurements of the chloride cells were examinedby Image Tools (2.0) image analysis software.Results: In the cortisol treatment there were 492 chloride cells per mm2 of the gill epitheliumwhich was significantly (p = 0.01) higher than the control group (289 chloride cells).The lengths of chloride cells were 13.9325 ± 0.5 μm and 16.0935 ± 0.5 μm in the cortisoland control groups, respectively; as reported, the length was significantly smaller in thecortisol group (p = 0.02). The widths of the chloride cells were 7.718 ± 0.3 μm and 7.922± 0.4 μm in the cortisol and control groups which were without any significant differences.Both the dispersion and numbers of chloride cells in four locations (on the filament, basementof the lamellae, interlamellar region and on the lamellae) were significantly different(p = 0.01) between the two experimental groups.Conclusion: exogenous cortisol can cause significant cellular and morphometric changesin gills of the Persian sturgeon fry for their adaptation to salinity