Effect of quinalphos on testicular steroidogenesis in rats.

The effect of quinalphos (250 micrograms/kg i.p.) an organophosphorus insecticide treatment for 13 and 26-days on the testicular steroidogenic enzymes viz. 3 beta-Hydroxysteroid Dehydrogenase and 17 beta-Hydroxysteroid Dehydrogenase, as well as cholesterol content and histology of the testes of the Wistar strain rats was studied. The time duration of 13 days is approximately equivalent to one cycle of the seminiferous epithelium in Wistar strain rats. Treatment of quinalphos for 13 days failed to produce any effect on the relative weights of the testes and accessory sex glands. However, significant inhibition of 3 beta-HSD activity and increased cholesterol level in testis were observed. The rats treated for 26 days similarly showed a highly significant inhibition of the activity of both 3 beta-HSD and 17 beta-HSD. The relative weights of the testes and accessory sex glands were also significantly reduced. Histological examination of the testis revealed that quinalphos treatment produced detrimental changes in the seminiferous epithelium. Treatment with quinalphos for 13-days produced no toxic effect with the exception of a significant increase in serum alkaline phosphatase. However, after 26-days of treatment toxicity was significantly increased as reflected on serum transaminases, phosphatases and blood urea levels of rat. Present study indicated that quinalphos impairs testicular functions in rats.