Endocrine disrupting effects of benzotriazole in rare minnow (Gobiocypris rarus) in a sex-dependent manner

Abstract

Benzotriazole (BT), an anticorrosive agent, is widely used in industrial applications and household dishwashing agents. Despite its reported toxicity to aquatic organisms, little is known about its endocrine disrupting effects. In this study, adult Chinese rare minnows (Gobiocypris rarus) were exposed to 0.05, 0.5, and 5mgL−1 BT for 28d. The pathological damage in liver was associated with hypertrophy of the hepatocytes, nuclei pyknosis and vacuolization at 5mgL−1 groups. Additionally, the degeneration of the ovary and the stimulation of spermatogenesis were observed at 5mgL−1 groups. The plasma 17β-estradiol level was significantly increased in the males but decreased in the females at 5mgL−1 (p<0.05). In the brain, the up-regulation of CYP19B, GnRHs, and LHβ mRNA was detected across all doses (p<0.05). In the gonad, the transcriptional levels of StAR, CYP11A, 3βHSD, CYP17, 17βHSD, and CYP19A were generally decreased in the males at 5mgL−1 (p<0.05), whereas these genes, except for 3βHSD, were significantly increased in females at all concentrations (p<0.05). Moreover, the expression level of VTG in the livers from all exposure groups was significantly increased compared with controls (p<0.05). Taken together, our results indicate that BT could adversely affect the rare minnows in a sex-dependent manner.