The effect of clomiphene citrate isomers on human granulosa-lutein cells in culture

Clomiphene citrate inhibits gonadotropin-induced ovulation by reducing cyclic adenosine 3',5'-cyclic monophosphate and prostaglandin E2 levels in rat ovary

OBJECTIVE

To determine whether clomiphene citrate (CC) inhibited gonadotropin-induced ovulation by reducing cyclic adenosine 3',5'-cyclic monophosphate (cAMP) and prostaglandin E2 (PGE2) levels in ovary. If so, to determine whether E2 coadministration could protect against these effects of CC.

DESIGN

A controlled prospective study.

SETTING

Laboratory research setting in the department of reproductive biomedicine at a national research institute in India.

ANIMAL(S)

Sixty sexually immature female rats that were 24-25 days of age.

INTERVENTION(S)

The sexually immature female rats were given a single injection (10 IU i.m.) of pregnant mare serum gonadotropin. After 48 hours, the rats were given single injections of hCG (10 IU) along with CC, with or without E2, for 16 hours.

MAIN OUTCOME MEASURE(S)

Number of superovulated COCs, ovary and uterus weight, FSH and LH levels in serum, and cAMP and PGE2 levels in ovary.

RESULT(S)

The superovulatory dose of gonadotropins significantly increased ovary and uterus weights, cAMP and PGE2 levels in ovary, and serum levels of FSH and LH. Coadministration of CC (10 mg/kg body weight) significantly reduced levels of cAMP, PGE2 in the ovary, ovary and uterus weights, and ovulation rate, whereas FSH and LH levels were not significantly altered. Supplementation of E2 protected against these inhibitory effects of CC and augmented levels of FSH and LH in serum.

CONCLUSION(S)

Clomiphene citrate inhibited gonadotropin-induced ovulation by reducing cAMP and PGE2 levels in the ovary, and E2 protected against these effects of CC on gonadotropin-induced ovulation in rat.

Estradiol protects clomiphene citrate–induced apoptosis in ovarian follicular cells and ovulated cumulus–oocyte complexes

OBJECTIVE

To determine whether clomiphene citrate (CC) reduces E(2) level in the ovary and circulation and induces apoptosis in ovarian follicular cells and ovulated cumulus-oocyte complexes (COCs). If yes, to determine whether E(2) coadministration could protect against these adverse effects of CC.

DESIGN

A controlled prospective study.

SETTING

Laboratory research setting.

ANIMAL(S)

Ninety sexually immature female rats that were 24-25 days of age.

INTERVENTION(S)

The immature female rats were injected with a single dose of 10 IU of pregnant mare serum gonadotropin. After 48 hours, 10 IU of hCG along with 10 mg of CC per kilogram of body weight, with or without 2.0 mg of E2 per kilogram of body weight were coadministered. After 16 hrs, the rats were killed; COCs were collected from oviduct and ovaries were isolated.

MAIN OUTCOME MEASURE(S)

Number of superovulated COCs, oocyte morphology, E2 level in ovary and serum, histology of ovary, DNA fragmentation, and bax protein expression in ovary and COCs.

RESULT(S)

The number of COCs and E2 level in ovary and serum were reduced, whereas membrane blebbing in oocytes, bax protein expression, and DNA fragmentation in ovarian follicular cells and ovulated COCs were induced after CC treatment. These adverse effects of CC were protected against if animals were coadministered with E2.

CONCLUSION(S)

Clomiphene citrate-induced apoptosis in ovarian follicular cells (probably granulosa cells), thereby reducing E2 level in ovary and circulation that might have resulted in poor development and maturation of oocytes leading to reduced ovulation.

Differential expression of endometrial integrins and progesterone receptor during the window of implantation in normo-ovulatory women treated with clomiphene citrate

OBJECTIVE

To assess the effect of clomiphene citrate (CC) on endometrial epithelial integrins and P receptors (PR) during the window of implantation.

DESIGN

Controlled, prospective, clinical study.

SETTING

Teaching hospital and university research laboratory.

PATIENT(S)

Thirty-one fertile, normo-ovulatory women participated in this trial. Thirteen women exhibited a CC-stimulated cycle with 50 mg on days 5-9, and 18 women with spontaneous menstrual cycles served as controls.

INTERVENTION(S)

Endometrial biopsies in the midluteal phase.

MAIN OUTCOME MEASURE(S)

Immunohistochemical determination and endometrial cellular localization of alpha1, alpha v, beta3, and alpha4 epithelial integrins and PR during the window of implantation. The staining intensity was assessed by a semiquantitative index (HSCORE) and compared by nonparametric Mann-Whitney test.

RESULT(S)

Higher plasma levels of P and E2 and delayed histologic dating of the endometrium (38%) were features of CC-treated women. In addition, a low epithelial beta3 integrin expression and persistent PR were observed in glandular epithelial cells of "out-of-phase" endometrial biopsies from CC-treated women. In contrast, in "in-phase" biopsies, neither epithelial PR nor beta3 integrin were different from spontaneous control cycles. There was no difference in the expression of alpha1, alpha v, and alpha4 between the groups studied.

CONCLUSION(S)

The administration of clomiphene produces aberrant endometrial beta3 integrin expression in conjunction with a failure in the down-regulation of PR during the window of implantation in a significant number of normo-ovulatory women, notwithstanding the higher plasma P levels. Therefore, CC might affect the expression of endometrial receptivity markers.

Serum concentrations of enclomiphene and zuclomiphene across consecutive cycles of clomiphene citrate therapy in anovulatory infertile women

OBJECTIVE

To determine the serum concentrations of enclomiphene and zuclomiphene across consecutive cycles of clomiphene citrate treatment in anovulatory infertile women.

DESIGN

Prospective cohort.

SETTING

Tertiary institutional infertility clinic.

PATIENT(S)

Fourteen consenting anovulatory infertile women receiving standardized, cyclic, incremental treatment with clomiphene citrate for ovulation induction.

INTERVENTION(S)

Clomiphene citrate treatment (50-150 mg/d, cycle days 5-9), titrated to the minimum effective ovulation-inducing dose, was administered for three to six total cycles. Blood samples were obtained on cycle days 3 and 10 in each treatment cycle.

MAIN OUTCOME MEASURE(S)

Serum concentrations of enclomiphene and zuclomiphene.

RESULT(S)

Cycle day 3 zuclomiphene levels were below assay limits in all initial cycles, increased progressively across three consecutive cycles, and thereafter plateaued. Cycle day 3 enclomiphene concentrations were uniformly undetectable. Cycle day 10 enclomiphene levels increased with dose administered, but these observations were not statistically significant.

CONCLUSION(S)

Clomiphene citrate induction of ovulation results in an isomer-specific systemic accumulation of zuclomiphene across consecutive cycles of treatment. The combined maximum concentration of enclomiphene and zuclomiphene attained in practice approximates 100 nmol/L and is generally well below levels previously demonstrated to have adverse effects in vitro.