Vitellogenin (salmonid) EIA Kit

Cimetidine is a histamine H2-receptor antagonist used for treatment of gastrointestinal disorders. It is often detected in aquatic environments, but its ecotoxicological effects have not been well studied. Thus, ecotoxicity of cimetidine was evaluated using Daphnia magna and Moina macrocopa, and zebrafish (Danio rerio), and a predicted no effect concentration (PNEC) was derived. In D. magna, 48 h immobilization EC50 was determined at 394.9 mg L-1. However, reproduction damages in D. magna were not found even at the maximum exposure level (30 mg L-1). For M. macrocopa, 48 h EC50 was found at 175.8 mg L-1 and the 7 d reproduction no observed effect concentration (NOEC) was 1.1 mg L-1. For D. rerio, 40 d growth NOEC was determined at 100 mg L-1, the highest experimental concentration. The PNEC of cimetidine was estimated at 0.1 mg L-1 based on M. macro copa 7 d reproduction NOEC. In 14 d adult zebrafish exposure, endocrine disruption potentials of cimetidine were observed. In male, decrease in plasma 17 beta-estradiol and testosterone levels, up-regulation of gonadal cyp17, and down-regulation of hepatic era were observed at 300 mg L-1. In female, increase in plasma E2 level and down-regulation of hepatic cyp1a were noted at 3 mg L-1. Endocrine disruption effects were also observed in early life stage exposure. Up-regulation of er beta at 17 d, and cyp19a and vtg at 40 d post fertilization were detected at 100 mg L-1, and co-occurrence of ovary and putative testis was observed at as low as 1.1 mg L-1. The results indicate that there is little evidence for cimetidine to cause direct ecological impact at the current ambient levels in the aquatic environment. However potential consequences of endocrine disruption following long-term exposure in aquatic environment deserves further investigation. (C) 2015 Elsevier Ltd. All rights reserved.

This study aimed at analyzing the energetic substrate (ES) in the main storage tissues of Steindachneridion parahybae, throughout the reproductive cycle in captivity. Differently from wild, in captivity, feeding is not interrupted during the reproductive period, the females do not spawn spontaneously, and they are sedentary. Adult females were sampled monthly and based on their histology and gonadosomatic index (GSI), ovaries were classified into: previtellogenic (PRV), vitellogenic (VTG), and regression (REG) stages. Ovaries at the VTG stage showed higher protein and lipids levels than at the PRV stage with a positive correlation between these substrates and the GSI. Muscle was the main source of proteins transferred to the ovaries, according to the negative correlation between these organs. Lipids remained unchanged in the liver, which is an important supplier in vitellogenesis, a pattern that probably occurs due to the continuous feeding. Muscular glycogen levels were higher at the VTG and REG than at the PRV stages. Plasma triglycerides were also higher during REG, while glucose levels were more elevated during the VTG stage. These results suggest that with constant food supply, the pattern of deposition of ES in S. parahybae is different from that described for other wild potamodromous species.