The action of various steroid hormones on the testis.
Small doses of testosterone propionate or testosterone in the rat or mouse result in lower testis weight, while larger doses do not produce this effect. Large doses of androgens and progesterone counteract the testis atrophy produced by estrogens and nonspecific damaging agents. Deoxycorticosterone acetate and estrogens also inhibit gonadotrophic hormone production and thus cause testicular atrophy, but they have not been shown to have any testis-stimulating effect. Androgens, estrogens, progesterone, or desoxycorticosterone acetate alone or in combination pr oduce atrophy of the Leydig cells at any dose level tested. It is thought that in the case of the androgens this represents a condition in which overdosage with a certain hormone causes involution of the cells normally responsible for its elaboration; in the case of the other hormones, it is an example of "transferred compensatory atrophy," where overdosage with a (usually) related hormone produces involution of the endocrine cells.(AUTHORS', MODIFIED)