Histopathological and estrogen effect of pentachlorophenol on the rare minnow (Gobiocypris rarus)

Pentachlorophenol (PCP), a typical organic pollutant and environmental endocrine disruptor, has been extensively used as a pesticide and biocide worldwide. In this study, the effects of PCP on the histological and hepatic system of the rare minnow (Gobiocypris rarus) were evaluated. Vitellogenin (VTG) was used as a biomarker to evaluate the estrogen effect of PCP. The results revealed that VTG was highly expressed and PCP exposure had histopathological effects on the rare minnow. Plasma and hepatic VTG concentrations increased when female rare minnows were exposed to a parts per thousand yen80 mu g/L PCP and male rare minnows were exposed to 40 mu g/L PCP (p < 0.05), which suggested that the VTG expression was evoked by PCP exposure. The results indicated that both plasma and liver tissue were suitable for VTG quantification. A significant decrease in the mRNA level of hepatic estrogen receptor-alpha (ER alpha) in male or juvenile was observed after exposure to a parts per thousand yen80 or a parts per thousand yen8 mu g/L PCP, respectively; in contrast, increased mRNA levels of ER beta 1, ER beta 2, VTGI, and VTGII in male or juvenile were detected after exposure to a parts per thousand yen80 or a parts per thousand yen8 mu g/L PCP, respectively. These results suggested that PCP has an estrogen effect and exists within different endocrine-disrupting pathways from other environmental contaminants. As such, VTG mRNA expression in the rare minnow may require transcription of the ER beta 1 and ER beta 2 genes.