Effects of atratone on hormone-dependent reactions in hypothalamus, pituitary and prostate gland

Abstract

The effect of atratone, a selective s-triazine herbicide, on specific reactions in hypothalamus, pituitary and prostate gland was studied. It was found that atratone influenced the biosynthesis of LRF at the hypothalamic level. Increased concentrations of atratone from 2.5 to 8.0 mmol inhibited the synthesis of LRF from 22% to 94%. The presence of atratone (0.4 mmol) in pituitary inhibited the activity of 5α-reductase in experiments conducted in vitro and in vivo (s.c. 0.1 mg of atratone/100 g b.wt.) for approximately the same amount (80%). The presence of atratone inhibited the 5α-dihydrotestosterone (5α-DHT) binding to receptor proteins in rat ventral prostate cytosol. It was found by the microcalorimetric technique that 5α-DHT was bound exothermically to cytosol receptors, while in the presence of 0.4 to 2 nmol/s of atratone the energetic level was changed and the binding was endothermic. In sucrose density gradient separation, the presence of 0.4 or 1 mmol of atratone decreased the binding of 5α-DHT to specific receptors in the 8S fraction, which is further proof of the blocking effect of atratone in the hormone-dependent reactions.