An effect in vivo of clomiphene on the rate of conversion of androstenedione-C14 to estrone-C14 and estradiol-C14 by the canine ovary

Estrogenic and antiestrogenic activities of anordiol: a comparison of uterine and vaginal responses with those of clomiphene citrate

Anordiol (2 alpha,17 alpha-diethynyl-A-nor-5 alpha-androstane-2 beta,17 beta-diol) has been variously characterized as an estrogen and as an antiestrogen. To more completely understand the pharmacological properties of this contraceptive steroid, simultaneous responses were studied in uterine, vaginal, and hepatic tissues. Rats received 4 daily sc injections with either anordiol, clomiphene citrate (CC), or the vehicle alone (C+) starting on the first day of pseudopregnancy. Uteri were traumatized on day 4 of pseudopregnancy, and rats were sacrificed 5 days later. A pseudopregnant group without uterine trauma served as a negative control (C-). Mean uterine weights per animal and cytosolic estrogen (EcR) and progesterone (PcR) receptor activities per g of DNA were all 5- to 7-fold greater in the C+ group than in the other groups (all p < 0.05). However, anordiol and CC suppressed uterine weight without suppressing the stromal proliferative response; the DNA content of the uteri of anordiol- and CC-treated rats was similar to that of C+ rats. Vaginal tissue exhibited estrogenic responses to anordiol and CC with an increase in epithelial stratification compared to the C+ and C- groups even though no difference in levels of EcR/g of DNA were expressed 5 days after the last antiestrogen dose. Binding affinities and serum E2 and progesterone (P) concentrations were not statistically different among the groups. In conclusion, anordiol produced responses in the uterus and vagina of the pseudopregnant rat which were indistinguishable from those of CC, and, therefore, we conclude that anordiol acts on these tissues as an antiestrogen.

Follicular fluid steroid content and in vitro steroid secretion by granulosa-lutein cells from individual follicles among different stimulation protocols for in vitro fertilization-embryo transfer

The in vitro steroidogenic capacity of granulosa-lutein (G-L) cells aspirated from individual follicles during cycles of in vitro fertilization-embryo transfer was examined and compared among three different stimulation protocols: human menopausal gonadotropins (hMG), clomiphene citrate (CC) and hMG, and follicle stimulating hormone (FSH). In addition, the clinical outcome of the patients in each protocol was examined. After 3 days of culture in basal medium, fresh medium with or without androstenedione (A) (10(-7) M) was added for 24 hr, at which time medium was obtained for measurement of progesterone (P) and estradiol (E) content. Follicular fluid (FF) P, E, and A were measured in each follicle and compared among protocols. FF from individual follicles in patients stimulated with FSH contained higher levels of P compared to FF from patients stimulated with hMG or CC/hMG, while E was higher in patients stimulated with CC/hMG compared to FSH or hMG. FF levels of A were not significantly different among the protocols. In vitro steroid secretion revealed a progressive increase in P secretion in contrast to decreasing E secretion when one compares CC/hMG, hMG, and FSH. Patients undergoing ovarian hyperstimulation with FSH had significantly more atretic oocytes identified at the time of oocyte harvest compared to patients undergoing ovarian hyperstimulation with CC/hMG or hMG. The hMG protocol yielded significantly fewer fertilized oocytes, cleaved embryos, and transferred embryos, compared to the CC/hMG and FSH protocol, however, there was no significant difference in pregnancy rate among the three protocols. These data demonstrate that individual follicles contain G-L cells with markedly different abilities to luteinize in vitro as assessed by steroid secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

A comprehensive dose-response study of clomiphene citrate for enhancement of the primate ovarian/menstrual cycle

Despite the increasing use of clomiphene citrate (CC) in normally cycling women undergoing in vitro fertilization, comprehensive data on the dose-response effects of the drug are unavailable. Twenty-four adult, normally cycling monkeys were given CC on cycle days 5 through 9 in doses ranging from 1 mg/kg to 10 mg/kg. Serum estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and progesterone were measured daily. CC stimulated an early, attenuated rise in serum LH which correlated with subsequent follicle development. Concurrently, serum E2 rose to preovulatory levels. No significant increase in serum FSH concentration was seen as a result of CC therapy. No correlation was seen between CC dose and peak levels of E2, LH, or FSH. The ovulatory status of the treatment cycles was also independent of dose. The factors that modulate these hormonal changes may involve direct effects of CC, estrogen feedback, and/or ovarian factors as yet uncharacterized. The individual variation of ovarian response, however, appears to be independent of the dose of CC.

The in vivo and in vitro effects of clomiphene citrate on ovulation, fertilization, and development of cultured mouse oocytes

Clinical data indicate a high rate of discrepancy between ovulation and pregnancy rates and a high abortion rate in anovulatory women treated with clomiphene citrate. An animal model was used to examine the in vivo and in vitro effects of the drug on fertilization and preimplantation development. This work indicates that mice treated with clomiphene in the early follicular phase of pregnant mare's serum-induced cycles show a dose-dependent decrease in ovulated oocytes. No effect was seen on the further development of these ova. When the drug was administered in the late follicular phase, a dose-dependent decrease was seen in the rate of successful copulation, ovulation, and embryo development. Concomitant 17 beta-estradiol treatment reversed the copulatory, ovulatory, and developmental effects of clomiphene. A short in vitro treatment of oocytes with clomiphene prior to in vitro fertilization resulted in an increased proportion of degenerated and unfertilized ova. Moreover, this treatment caused a dose-dependent decrease in blastocyst formation.

Effect of clomiphene citrate upon amount and duration of human menopausal gonadotropin therapy

Human menopausal gonadotropin (HMG) was given to 10 patients who failed to ovulate after treatment with clomiphene citrate. Prior to one or more treatment courses, 200 mg. of clomiphene were administered daily for 5 days; at least one other treatment course was not preceded by clomiphene. Before therapy, progesterone in oil was administered and serum FSH, LH, and estrogen were measured. Those patients who had normal serum FSH levels and had withdrawal bleeding following progesterone had a reduction in amount and duration of HMG requirements for those patients with low serum FSH who did not withdraw. Thus, sequential clomiphene-HMG therapy is of benefit only for those women with normal serum FSH levels and is the treatment of choice.