REGULATION OF PLASMA OESTROGENS IN NORMAL ADULT MALES

Abstract

ABSTRACT The response of plasma oestradiol (Oe2), oestrone (Oe1) and testosterone (T) to stimulation of the Leydig cells with human chorionic gonadotrophin (HCG) and to suppression with a synthetic androgen was ascertained in normal adult males. Three days after daily im injections with 5000 IU HCG, Oe2 increased from 1.93 to 5.66 ng/100 ml (mean of 12 subjects), Oe1 from 2.76 to 4.99 ng/100 ml, and T from 547 to 990 ng/100 ml. Thus, Oe2 increased on the average 3.07 times, Oe1 1.90 times, and T 1.86 times. Four days after oral administration of daily 40 mg fluoxymesterone (9α-fluoro-11β-hydroxy-17α-methyltestosterone), T decreased from 521 to 99.8 ng/100 ml (19.3 % of the control level, mean of 12 subjects), Oe2 from 1.93 to 0.66 ng/100 ml (34.9 % of the control level), and Oe1 from 3.14 to 2.23 ng/100 ml (72.5 % of the control level). Highly significant correlations were found between the pre-stimulation levels of Oe2 and Oe1, between the increments of Oe2 and Oe1 and of Oe2 and T after HCG stimulation.