Alternations in neuroendocrine and endocrine regulation of reproduction in male goldfish (Carassius auratus) following an acute and chronic exposure to vinclozolin, in vivo

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English. The fungicide vinclozolin (VZ) is in use globally and known to disrupt reproductive function in male. The present study tested the hypothesis that VZ disrupts testicular function in goldfish (Carassius auratus) by affecting brain-pituitary-testis axis. Goldfish were exposed to 100,400 and 800 mu g/L VZ and 5 mu g/L 17 beta-estradiol (E-2) for comparison. In VZ treated goldfish, 11-ketotesteosterone (11-KT) secretion was changed depending on dose and duration period of treatment. Following 7 days of exposure, 11-KT was decreased in goldfish exposed to 800 mu g/LVZ, while it was increased in goldfish exposed to 100 mu g/L VZ after 30 days of exposure. Circulating E-2 level was unchanged in VZ treated goldfish, however the E-2/11-KT ratio was increased in a concentration-related manner. In E-2 treated goldfish, circulatory 11-KT and E-2 levels were decreased and increased, respectively, which resulted in an increase in the E-2/11-KT ratio. Exposure to VZ at 100 E(2)g/L caused a significant increase in the circulatory luteinizing hormone (LH) after 30 days. In E-2 treated fish circulatory LH was decreased, significantly. Transcripts of genes encoding gonadotropin-releasing hormone and androgen receptor in the brain, and those of genes encoding LH and follicle-stimulating hormone receptors, StAR, CYP17, and 3 beta-HSD in the testis changed in VZ-treated goldfish depending on concentration and period of treatment. mRNA of genes encoding vitellogenin and estrogen receptor in the liver and cytochrome P450 aromatase in the brain were increased in E-2-treated goldfish. The results suggest that VZ-induced changes in 11-KT were due to disruption in brain-pituitary-testis axis and provide integrated characterization of VZ-related reproductive disorders in male fish.