Suppressive effect of quinalphos on the activity of accessory sex glands and plasma concentrations of gonadotrophins and testosterone in rats.

Biochemical estimation of prostatic acid phosphatase and fructose content in accessory sex glands, along with radioimmunoassay of plasma gonadotrophins (FSH and LH) and testosterone were performed in Wistar rats following treatment with quinalphos, an organophosphorus insecticide, for 13 and 26 days. Prostatic acid phosphatase activity and fructose content of the accessory sex glands, and plasma levels of testosterone and FSH were significantly lower in all rats treated with quinalphos. However, the degree of inhibition was more extensive in the 26 day-treatment group who, in addition also exhibited a significant reduction in relative weights of the testes and accessory sex organs, and plasma levels of LH. All these adverse effects of quinalphos were prevented when exogenous HCG was administered in concomitant with the insecticide for 26 days. These results suggest that quinalphos may exert a suppressive effect on the functional activity of accessory sex glands by decreasing testicular testosterone production following inhibition of pituitary gonadotrophins release.