Comparison between testosterone enanthate-induced azoospermia and oligozoospermia in a male contraceptive study. I: Plasma luteinizing hormone, follicle stimulating hormone, testosterone, estradiol, and inhibin concentrations
Wallace, E.M.; Gow, S.M.; Wu, F.C.
Journal of Clinical Endocrinology and Metabolism 77(1): 290-293
1993
ISSN/ISBN: 0021-972X PMID: 8325955 DOI: 10.1210/jcem.77.1.8325955Document Number: 335022
In the UK, 28 healthy, fertile, white 23-40 year old men received an intramuscular injection of 200 mg testosterone enanthate (TE) during a male contraceptive efficacy trial. Only 17 men achieved azoospermia. Researchers used ultrasensitive immunofluorometric assay to measure gonadotropins and took venous blood samples right before the next TE injection to measure circulating steroid and inhibit (IN) levels. They wanted to determine whether gonadotropin suppression or changes in circulating steroid and IN levels during TE administration maintain some level of spermatogenesis in the 11 oligozoospermic men. At 5 weeks after beginning TE administration, azoospermic men experienced a more rapid fall in sperm density than oligozoospermic men (18.7 x 1 million/mL vs. 48.4 x 1 million/mL; p .05). In both groups, luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were always lower than the assay detection limit during TE administration. On the other hand, after TE administration, testosterone (T) and estradiol (E2) levels increased 2.5 times while IN levels fell 2.5 times. Azoospermic men recovered sperm density at or above 20 x 1 million/mL at a slower rate than did oligozoospermic men (p .01). They had significantly higher LH and FSH levels during the recovery phase compared to baseline levels and to those of oligozoospermic men (p .05). Yet, circulating levels of T, E2, or IN were essentially the same in both groups. These results suggest that neither incomplete suppression if pituitary gonadotropins nor differences in sex steroid or IN levels would likely account for the differences in the degree of spermatogenic suppression in the 2 groups of men receiving exogenous TE administration. The faster rise in gonadotropins in azoospermic men during recovery may intimate that they experience a more profound degree of spermatogenic suppression.