Inhibition of HCG induced testosterone increase by melatonin-free pineal extract in the rat.
The effect of a pineal treatment on rat testosterone under conditions of exogenous HCG stimulation was followed-up. Administration of 2 ml/day/animal of a melatonin-free pineal extract for 3 days lowered by 23% (p less than 0.01) the serum level and by 32% (p less than 0.02) the testis content in testosterone, both values being increased by concomitant administration of 50 UI HCG per animal. In other words, the melatonin-free pineal extract inhibited partially the testis response to HCG. The antiandrogenic action of the pineal extract is discussed.
D000818:Animals; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D010870:Pineal Gland; D051381:Rats; D013737:Testis / Q000032:analysis; D013739:Testosterone / Q000032:analysis / Q000096:biosynthesis*; D014020:Tissue Extracts / Q000494:pharmacology*
D006063:Chorionic Gonadotropin; D014020:Tissue Extracts; D013739:Testosterone; D008550:Melatonin