SPERMATOGENIC REBOUND PHENOMENON AFTER ADMINISTRATION OF TESTOSTER ONE PROPIONATE*

Abstract

Observations on the effect of testosterone propionate were made on 5 men 27 to 34 yrs. of age, who had barren marriages because of an oligospermia of undetd. etiology. Their total sperm counts varied from 31 to 63 million. They were healthy, well nourished individuals. The testis were, with the exception of one patient, grossly normal. The physical examinations and various routine laboratory procedures, including basal metabolic rats, revealed no abnormalities. Assays of urinary 17-ketosteroids and gonadotropins were not carried out in this group. Testicular biopsies were done and revealed a defect in the spermatogenic mechanism which was considered to be reversible. The 5 patients were made azoospermic or nearly so, by the intramus. admn. of 50 mg. of testosterone propionate 3 times a week. Sperm counts were done at 6-8 week intervals. The total dose of testosterone propionate given ranged from 1500 mg. to 2550 mg. When the patients became azoospermic, treatment was stopped and seminal fluid analysis made at 6 to 8 week intervals. It was observed that there was a gradual increase in the number of sperms that far exceeded pretreatment levels. The height of this spectacular rebound phenomena occurred from 4-7 mos. after treatment was discontinued. Testicular biopsies were done on 3 of the 5 patients at the presumed height of the rebound phase. The histologic pictures of these 3 biopsies showed an increase in the spermatogenic activity of the maturation processes as compared to the pretreatment biopsy specimens. At the present time it is not known whether this response is peculiar to an androgenic substance or whether it can be elicited by other agents.