The effect of clomid on estrogen secretion and metabolism

Clomiphene citrate augments follicle-stimulating hormone-induced luteinizing hormone receptor content in cultured rat granulosa cells

Although clomiphene citrate (CC) has been widely used for ovulation induction, the mechanism of its pro-fertility effect is not entirely clear. Because CC augments ovarian aromatase activity, the effect of CC on follicle-stimulating hormone (FSH)-induced luteinizing hormone (LH) receptor content was examined in primary cultures of rat granulosa cells. Control cultures contained low LH receptor content, whereas FSH stimulated LH receptor formation in a dose-dependent manner. The concomitant addition of CC enhanced FSH potency as shown by a decrease in the ED50 for FSH by 2.2-fold. Some cells were treated with a low concentration of FSH (12 ng/ml) in the presence or absence of increasing concentrations of CC (10(-8) M to 10(-6) M). The enhancement of FSH-stimulated LH receptor formation was found to be CC dose dependent, with an ED50 of 6 X 10(-8) M. Thus, CC may play a direct ovarian role in the enhancement of FSH-stimulated LH receptors. The gonadal action of this compound may be relevant in understanding the efficacy of CC in ovulation induction.

Antiestrogenic action of high-dose clomiphene in primates pituitary augmentation but with ovarian attenuation

Since the dominant follicle is selected by days 5 to 7 of the menstrual cycle, we assessed the differential effects of high-dose clomiphene (25 mg daily) by giving 5-day courses either before (days 1 to 5), during (days 5 to 9), or after (days 9 to 13) emergence of the selected dominant follicle in monkeys. Peripheral sera were obtained daily and assayed for follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17 beta-estradiol (E2), and progesterone (P); serial laparoscopies were performed. Rather than enhancement of gonadotropin-dependent folliculogenesis during clomiphene treatment cycles, ovulation was delayed in 18 of 18 treatment cycles. Interestingly, the interval from treatment to next ovulation lengthened when clomiphene was given in the late follicular phase. Consistently, the clomiphene treatment cycles were characterized by a marked decline of the serum E2 during the 5 days of therapy, despite concurrent elevations of pituitary gonadotropins in circulation, especially FSH. These data suggest that a direct antiestrogenic effect of clomiphene imparted ovarian refractoriness to the prevailing, even enhanced, gonadotropin levels. The vulnerability of follicular maturation to these attenuating effects of clomiphene was greatest in the late follicular phase, well after the dominant follicle had been selected. Even after this clomiphene-induced ovarian hiatus and eventual resumption of new follicle growth, the initial apparent ovulation led to latent, severe corpus luteum insufficiency.

The effect of clomiphene on uncastrated and castrated male transsexuals

Clomiphene was administered at a daily dose of 100 mg for 5 consecutive days to two groups of male subjects. There were three uncastrated male transsexuals (Group A) and nine castrated male transsexuals (Group B). In the uncastrated subjects Clomiphene enhanced the secretion of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T) starting from day 3 of treatment. The magnitude of the increment ranged from 150%--250% over the mean basal plasma level for LH, 113%--262% for FSH and 12%--68% for T. In contrast, Clomiphene suppressed both FSH and LH in the castrated subjects. Equal suppression of both the gonadotrophins were observed. The levels of FSH and LH in plasma on day 3 were suppressed to 66.4% and 66.2% of their respective mean basal levels. Two days after the termination of treatment, suppressions were maintained. These results suggest that Clomiphene acts as an anti-oestrogen in uncastrated male transsexuals and in castrated male transsexuals who have subphysiological levels of oestradiol it acts as a weak oestrogen.

Management of infertility resulting from anovulation

Recent methods for induction of ovulation in the woman are described. The only indication for use of these medications is induction of ovulation and pregnancy. In properly selected patients, the success rate is quite high, but treatment has undesirable side effects which occasionally may be severe.

Pituitary gonadotrophic and ovarian function in women treated with clomiphene citrate

Serial estimations of follicle-stimulating hormone (FSH) and luteinising hormone (LH), as well as of oestrogens and pregnanediol have been performed in the urine of 5 women suffering from a variety of gynaecological conditions associated with infertility who were treated with clomiphene citrate at different dose levels.

One subject became pregnant following medication; in the other 4 evidence for ovulation was present in one and was at best equivocal in the remaining 3. The effect of the compound on urinary FSH and LH levels was variable as was the pattern of urinary steroid excretion following medication; in 2 subjects a rise of oestrogen output preceded that of LH excretion. The study confirms previous observations indicating that atypical luteal function may follow clomiphene administration and underlines the fact that wide variations of hormonal response to the compound can occur.

Clomiphene-Test for Evaluation of Residual Pituitary Activity after Yttrium Implantation in Patients with Advanced Breast Carcinoma

It has been suggested that tumor regression following hypophyseal implantation of Yttrium sources is not always related to the endocrine effect of this procedure. It has been observed that although relief of pain was obtained in the majority of patients with bone metastases from breast cancer with hypophyseal implantation of radioactive Yttrium, only a small proportion showed endocrinological evidence of complete hypophyseal destruction. Nevertheless, it has been shown that patients with tumor regression after hypophyseal irradiation included a higher proportion with a marked fall in gonadotropin excretion than did the non-responding patients. In order to obtain more information on the residual pituitary ability to synthesize gonadotropins, after hypophyseal implantation of Yttrium, oral Clomiphene was administered to 3 women with advanced breast cancer treated by implantation of radioactive Yttrium twenty days before. One of these patients (12R-50) was subjected to bilateral ovariectomy 4 years before Yttrium implantation. In another patient (11R-61) the Clomiphene-test was done seven months after hypophyseal irradiation with Yttrium. The dose of Clomiphene used was 100 mg daily for five days. Urinary interstitial cell stimulating hormone (ICSH), determined by using competitive hemoagglutination based upon the cross-reaction between the antiserum to HCG and ICSH, estrogens (estrone and estradiol-17beta) and testosterone were determined before hand, after 5 days of treatment with Clomiphene (500 mg) and 4 days after clomiphene therapy. In all patients before clomiphene therapy, ICSH was present in the urine and its value was very elevated in the patient treated with Yttrium implantation 7 months before. After Clomiphene therapy, at 5th day of treatment, in three patients instead of observing, as expected, a rise in ICSH output, a rise in urinary estrogens was shown, together with a decrease in the urinary ICSH level. In these patients 4 days after Clomiphene therapy the urinary level of ICSH increased to high levels, whereas the estrogen level decreased. We suggest that Clomiphene acted upon the ovaries of these patients and the adrenals giving up an increase in urinary estrogens which inhibited the progressive rise of ICSH. In the absence of ovarian or adrenal activity, as in case (12R-59), shown by the absence of estrogens before and during Clomiphene therapy, Clomiphene can induce an early rise in urinary ICSH. There is still uncertainty as to the site of action of Clomiphene and two basic hormone changes have been put forward, one an initial rise in estrogens, the other a primary increase in gonadotropins. From our data we presume that either the hypothalamic-pituitary axis or ovary and adrenals may be the target organ for clomiphene. In this way the Clomiphene-test would give not only better information on the residual pituitary activity after radiological (or surgical) ablation but also on the relationship between the pituitary and peripheral endocrine organs in breast cancer patients.