Effects of Ε11-Testolactone on the Pituitary-Testicular Axis In Oligospermic Men*

Abstract

Ten men with idiopathic oligospermia were treated with Ε₁testolactone (Teslac), a potent inhibitor of conversion of androgens to estrogens. Teslac therapy caused a fall i n serum estradiol and estrone levels of 34%(P < 0.01) and 41% (P< 0.01), respectively, and a rise in serum testosterone and androstenedione of 47% (p < 0.02) and 70%(P < 0.01), respectively. The testosterone:estradiol ratio increased by 126% (23.5 ± 2.5 × HT(1) to 45.2 ± 5.0 × 10^-1; P < 0.01) and the androstene-dione:estrone ratio increased 231% (4.7 ± 0.6 × 10^-1 to 12.9 ± 2.0 × 10^-1; P< 0.01). Basal and LRH-stimulated serum gonadotro-pin levels were unaffected by these changes. Sperm density rose from 10.8 ± 2.5 to 19.8 ± 4.7 × 107ml (P < 0.01) and total sperm count from 26.8 ± 6.5 to 60.6 ± 14.3 × 10⁶ (P < 0.001). There was no significant change in motility or semen volume. Three of the wives became pregnant. There were no adverse effects of Teslac administration. These data suggest that Teslac may be an effective treatment for men with idiopathic oligospermia. Though the data do not clearly elucidate the mechanism of this effect, they are consistent with the possibility that Teslac’s lowering of estrogen levels may have been responsible for the improvement in spermatogenesis. The findings also suggest that moderate increases in the circulating androgen:estrogen ratio do not affect gonadotropin output in men.