Enclomiphene is an estrogen receptor (ER) modulator.1,2,3 It acts as an ER antagonist in humans, sheep, and rabbits and an ER agonist in rats.1,2,3 Enclomiphene (0.34 ?M) inhibits binding of 17β-estradiol in isolated rabbit uterus.2 It decreases E2-induced inhibition of follicle stimulating hormone (FSH) secretion in primary sheep pituitary cells in a concentration-dependent manner.3 Enclomiphene (0.25 and 0.5 mg/animal) inhibits spermatogenesis and decreases serum luteinizing hormone (LH) and testosterone levels in intact or castrated rats.4 Formulations containing enclomiphene have been used in the treatment of ovarian dysfunction.
1.Hill, S., Arutchelvam, V., and Quinton, R.Enclomiphene, an estrogen receptor antagonist for the treatment of testosterone deficiency in menIDrugs12(2)109-119(2009) 2.Wyss, R.H., Karsznia, R., Heinrichs, W.L., et al.Inhibition of uterine receptor binding of estradiol by anti-estrogens (clomiphene and CL-868)J. Clin. Endocrinol. Metab.28(12)1824-1828(1968) 3.Huang, S.-R., and Miller, W.L.Estrogenic and antiestrogenic effects of enclomiphene and zuclomiphene on gonadotropin secretion by ovine pituitary cells in cultureEndocrinology112(2)442-448(1983) 4.Weissenberg, R., Dar, Y., and Lunenfeld, B.The effect of clomiphene citrate and its Zu or En isomers on the reproductive system of the immature male ratAndrologia24(3)161-165(1992)