ÉTUDE COMPARATIVE DES EFFETS SEXUELS DES ANDROGÉNES NATURELS

Abstract

ABSTRACT A study was made of the activities exerted by the following naturally occurring androgens on the male sexual receptors of the capon and of the castrated male rat, and also of their inhibitory action on the oestrous cycle and gonadotrophic functions in the rat: testosterone, androsterone, androstenedione, adrenosterone, 11β-hydroxy-androstenedione, dehydroepiandrosterone, 17α-hydroxy-progesterone, and progesterone. When the effects of these androgens were investigated on a large number of receptors, the results revealed the differences in the spectrum of activity of each of the substances. Thus, for example, adrenosterone has an androgenic effect in castrated rats which is much greater than in the capon (corresponding to 50% and 5% respectively, of the activity of testosterone), whereas the difference in the androgenic effect exerted on the two species is much less marked in the case of androsterone and androstenedione. 17α-hydroxy-progesterone, on the other hand, displays marked activity on the capon's comb after local inunction, but has only a slight effect on the sexual adnexa of castrated rats. Of all the androgenic receptors investigated only the ventral prostate responds to treatment with progesterone. Of all the compounds included in this study, only 11β-hydroxy-androstenedione has an anabolic/androgenic ratio greater than testosterone, whereas with all the other compounds the ratio is less. Although the degree of inhibition exerted on the oestrous cycle is in all instances equivalent to less than 1/10 of that of testosterone, the anti-gonadotrophic activity as evidenced by experiments on parabiotic animals shows considerable variations from one steroid to the other. It is very high for androsterone and androstenedione (60% of that of testosterone), diminishes in the case of adrenosterone (20% of that of testosterone), and is even weaker in the case of 11β-hydroxy-androstenedione, dehydroepiandrosterone, 17α-hydroxy-progesterone, and progesterone, which has only 10% the activity of testosterone. The correlations between the different types of action and their possible implications are discussed.