The Endocrinology of Spermatogenesis in Birds

Abstract

THE effect of the administration of male hormones upon testes weight and spermatogenesis in both normal and hypophysectomized mammals has been studied extensively. Comparable studies with birds are limited and the results are contradictory due, it is believed, to variations in time of administration in relation to the normal stage of spermatogenesis, and to level of dosage. Male starlings were injected by Burger (1944) with 1.0 mg. testosterone propionate every 72 hours for periods of 26 to 36 days. Testes naturally in the later stages of spermatogenesis were unaffected while those in early stages showed an initial depression in size and activity by the androgen. Under continued treatment of light and androgen, spermatogenesis occurred but androgen depressed rather than stimulated the rate. In a second bird, the sparrow, Pfeiffer (1947) reported that testosterone propionate at the level of 0.25 mg. daily would stimulate the completion of spermatogenesis provided the testes . . .