EFFECT OF CLOMIPHENE ON AROMATIZATION OF STEROIDS BY THE HUMAN PLACENTA IN VITRO

Abstract

ABSTRACT Results of in vivo experiments in women (Smith et al. 1963) have raised the possibility that clomiphene per se may be capable of stimulating one or more of the enzyme systems involved in ovarian biosynthesis of oestrogens. In the in vitro experiments herein reported, the effect of adding this drug to a preparation of human placenta capable of converting certain C19 steroids to ring A phenols was investigated. The substrates were inert and radioactive testosterone and androstenedione. In each of 6 experiments involving, besides the controls, nine direct comparisons between the yields of oestrone with versus without clomiphene added, there was clear evidence that the addition of clomiphene increased the rate of this reaction. The conversion of radioactive precursors was increased by an average of 23.4%. Measured chemically, in the same experiments, the average increase was 27.0%. That the results reported are related to the stimulatory effect of this drug upon steroidogenesis in human ovaries remains to be proven.