Mouse Anti-Fish Vitellogenin Hybridoma [NWQ2]

Soy isoflavones (the phytoestrogens genistein, daidzein and glycitein) may act as estrogen receptor agonists or antagonists. The aim of this study was to examine the effect of dietary isoflavones on growth, reproduction and health in rainbow trout (Oncorhynchus mykiss). Rainbow trout fed three experimental diets containing different concentrations of isoflavones (0, 500 and 1,500 ppm). Growth, estrogenic activity, plasma estradiol levels, gonadal development, state of stress and histological changes in selected tissues were evaluated at the end of 70 days. Neither growth performance nor the relative mRNA levels of Insulin Growth Factor I (igf-I) in the liver were influenced by different levels of dietary isoflavones. Plasma and liver vitellogenin (VTG) protein levels and plasma 17-beta-estradiol (E-2) were unaffected by treatments, although the correlation between plasma levels of E-2 and VTG densitometry values was significant (p < .05). The fish gonadosomatic index (GSI) did not significantly differ among the three experimental groups but correlated with plasma VTG densitometry values (p < .05). Plasma, muscle and fin cortisol concentrations fell within the normal welfare range and were not correlated with isoflavone levels. Histologically, the distal intestine showed a normal morphology with well-differentiated enterocytes and in the liver hepatocytes were also normal. A supranuclear accumulation of lipid droplets in enterocytes and some lipid droplets in hepatocytes were observed in all tested groups, suggesting an impact of basal dietary lipid on transport/metabolism of fat in the fish. Overall, the present results suggest that the doses of isoflavones tested do not compromise rainbow trout reproduction, growth and health.

This study was conducted to measure 17 beta-estradiol (E2) levels in Laguna de Bay, Philippines and to examine feral male common carp for evidence of exposure to estrogenic pollutants. Analysis of water samples revealed E2 concentrations of 630 and 550 ng/L from the east and west bay of the lake, respectively. Plasma vitellogenin (VTG) in captured fish ranged from 506 to 4083 ng/mL. In comparison to the reference and west bay groups, fish from the east bay had higher plasma VTG concentrations and reduced gonadosomatic index (GSI). Ovotestis was not observed although some individuals had endocrine-related histopathological alterations in the testis. The degree of biologic effects induced by estrogenic pollutants in tropical freshwater systems like Laguna de Bay need to be further investigated to provide a better comprehension of the fates and effects of these compounds under tropical conditions.