Effect of stilbestrol on spermatogenesis of Rana hexadactyla lesson.

Stilbestrol in both a single injection and in a series of injections was administered in 2 groups of adult male frogs (Rana hexadactyla) in order to examine its inhibitory effects on spermatogenesis. The total dose given to each frog was 1.25 mg. A decrease in the relative testis weight of both groups was noted as compared with control animals. The split dose administration of stilbestrol significantly (p. less than .001) affected all 6 spermatogenetic stages as compared to controls. The single dose induced significant (p. less than .001) changes in primary and secondary spermatogonia as compared to controls. Possible modes of action for both split and single-dose administration are discussed.