Normoprolactinemic anovulation nonresponsive to clomiphene citrate: ovulation induction with bromocriptine**Supported in part by Sandoz Farmaceutica Ltd. (Chile) and Instituto de Estudios Medicos Avanzados, Santiago, Chile

Toxicology of octamethylcyclotetrasiloxane (D4)

Octamethylcyclotetrasiloxane (D₄) is a volatile cyclic siloxane used primarily as a monomer or intermediate in the production of some silicon-based polymers widely used in industrial and consumer applications and may be present as a residual impurity in a variety of consumer products. A robust toxicological data set exists for D_4. Treatment-related results from a chronic inhalation study conducted in rats are limited to mild effects on the respiratory tract, increases in liver weight, increases in the incidence of uterine endometrial epithelial hyperplasia, and a dose-related trend in the incidence of endometrial adenomas. The observed increases in liver weight appear to be related to the induction of hepatic metabolizing enzymes, similar to those that are induced in the presence of phenobarbital. D₄ is not mutagenic or genotoxic in standard in vitro and in vivo tests; therefore, the benign uterine tumors observed likely occur by a non-genotoxic mechanism. Results from mechanistic studies suggest that D₄ has very weak estrogenic and antiestrogenic activity, as well as dopamine agonist-like activity. In rats, D₄ exposure delays ovulation and hypothesized to prolong exposure of the uterine endometrium to endogenous estrogen. Though this mode of action may play a role in the development of benign uterine tumors in the rat, it is considered unlikely to occur in the human due to the marked differences in cycle regulatory mechanisms. Reproductive effects were observed following D₄ exposure in female rats. These effects appear to be related to a delay of the luteinizing hormone (LH) surge, which fails to induce complete ovulation in the rat. However, based on differences in ovulatory control in rats and humans, it appears these effects may be species-specific with no risk or relevance to human health. Results from pharmacokinetic studies indicate that dermal absorption of D₄ is limited, due to its high volatility and, if absorbed via dermal, oral or inhalation exposure, the majority of D₄ is rapidly cleared from the body, indicating bioaccumulation is unlikely.

N-Acetyl cysteine and clomiphene citrate for induction of ovulation in polycystic ovary syndrome: a cross-over trial

OBJECTIVE

To compare clomiphene citrate plus N-acetyl cysteine versus clomiphene citrate for inducing ovulation in patients with polycystic ovary syndrome.

DESIGN

Prospective cross-over trial.

SETTING

University teaching hospital and a private practice setting.

PATIENTS

Five hundred and seventy-three patients were treated with clomiphene citrate for one menstrual cycle among which 470 patients were treated with clomiphene citrate plus N-acetyl cysteine for another cycle. All women suffered from polycystic ovary syndrome.

INTERVENTIONS

Patients had clomiphene citrate 50-mg tablets twice daily alone or with N-acetyl cysteine 1,200 mg/day orally for 5 days starting on day 3 of the menstrual cycle.

OUTCOME MEASURES

Primary outcomes were number of mature follicles, serum E2, serum progesterone, and endometrial thickness. Secondary outcome was the occurrence of pregnancy.

RESULTS

Ovulation rate improved significantly after the addition of N-acetyl cysteine (17.9% versus 52.1%). Although the number of mature follicles was more in the N-acetyl cysteine group (2.1+/-0.88 versus 3.2+/-0.93), the difference was not statistically significant. The mean E2 levels (pg/ml) at the time of human chorionic gonadotropine injection, serum progesterone levels (ng/ml) on days 21-23 of the cycle, and the endometrial thickness were significantly improved in the N-acetyl cysteine group. The overall pregnancy rate was 11.5% in the N-acetyl cysteine group. Insulin resistance occurred in 260 patients (55.4%). There was no significant difference between the insulin resistance group (n = 260) and non-insulin resistance group (n = 210) as regards ovulation rate, number of follicles, serum E2 (pg/ml), serum progesterone (ng/ml), endometrial thickness (mm), or pregnancy rate.

CONCLUSION

N-Acetyl cysteine is proved effective in inducing or augmenting ovulation in polycystic ovary patients.

The effect of bromocriptine on the motility of human spermatozoa and its capacity to penetrate the cervical mucus

We investigated the direct effects of bromocriptine on the motility of the human ejaculated spermatozoa and its capacity to penetrate the cervical mucus (CM) in vitro. Washed sperm were incubated with a wide range of bromocriptine concentrations (0.005 to 5 mM). Progressive and total motility was evaluated after 15, 30, 60, and 180 minutes. No reduction of motility was observed at any concentration tested. Similar results were observed with semen samples. Failure to alter sperm motility was evident in samples with either good or reduced motility. Also, CM penetration as measured after 90 minutes by Penetrak assay (Serono Diagnostics, Randolph, MA) was not impaired by a concentration as high as 5 mM bromocriptine. We conclude that bromocriptine in a wide range of concentrations does not inhibit sperm motility nor does it impair the capability of the sperm to penetrate the CM. These data support the therapeutic use of daily vaginal bromocriptine for the treatment of infertility.