The impact of unabated stimulation by human chorionic gonadotropin on the steroid hormone environment of pregnant rats and the spontaneous expression of ovarian cysts in female progeny.

Unabated stimulation by low doses of human chorionic gonadotropin (hCG) induces ovarian cysts in pregnant rats. In order to determine the impact of these in vivo treatments on the hormonal milieu of pregnancy, and the potential impact of an aberrant cystic-ovary state during pregnancy on the resulting female offspring, pregnant rats were treated with either 0 (control), 1, or 3 IU hCG twice daily for at least 9 days, beginning on day 13 of pregnancy. Serum was harvested from control and hCG treated animals on days 15, 17, 19, and 22 of pregnancy.

Obligatory roles for follicle-stimulating hormone (FSH), estradiol and androgens in the induction of small polyfollicular ovarian cysts in hypophysectomized immature rats.

Immature hypophysectomized (HYPOXD) rats develop large, polyfollicular ovarian cysts in response to unabated, combined stimulation by subovulatory doses of human chorionic gonadotropin (hCG) and highly purified ovine follicle-stimulating hormone (FSH). Further, circulating amounts of androstenedione (A4) and estradiol (E2), but not testosterone or dihydrotestosterone (DHT), change in parallel with the development of these cysts. To determine the potential roles of either A4 or E2 at the level of the ovary in the induction of ovarian cysts, pellets containing either (1) cholesterol (placebo; controls); (2) A4; or (3) E2 were administered subcutaneously (sc) to immature HYPOXD rats.

Synergistic effects of insulin-like growth factor-I and human chorionic gonadotropin in the rat ovary.

Insulin and low doses of lutenizing hormone (LH) activity (human chorionic gonadotropin [hCG]) act synergistically in the rat to produce anovulation, large ovarian cysts, and elevated plasma androstenedione levels. Further, both insulin and insulin-like growth factor-I (IGF-I) affect the ability of gonadotropins to enhance both ovarian theca and granulosa cell function in vitro. The present series of experiments were performed to determine if recombinant human IGF-I (rhIGF-I) can act in a manner similar to insulin when combined with subovulatory doses of hCG in adult normally cycling rats.

Insulin has a biphasic effect on the ability of human chorionic gonadotropin to induce ovarian cysts in the rat.

Hyperinsulinemia enhances the ability of subovulatory doses of human chorionic gonadotropin (hCG) to induce ovarian follicular cysts in the rat. To determine the relative contribution of these hormones to the development of ovarian cysts, adult female rats were treated with either (1) vehicle alone (controls), (2) a high-fat diet (HFD) to control for the effects of weight gain, (3) 1.5 to 6 IU hCG twice daily plus 6 U insulin (Ins)/d, or (4) 1.

Changes in the forward and reverse metabolism of aromatizable androgens during the development of large ovarian cysts in the pregnant rat.

Twice-daily treatments with subovulatory doses of hCG result in the development of large ovarian cysts that possess the capacity to produce preovulatory amounts of estradiol (E2) in the presence of exogenous substrate (Biol Reprod 1991; 45:34-42). To determine the effects of prolonged stimulation by subovulatory doses of LH-like activity on the ability of ovarian follicles to produce aromatizable androgens and their metabolites and on the capacity of similar follicles to metabolize exogenous androstenedione (A4) and testosterone, pregnant rats were treated with either 0 (control), 1, or 3 IU hCG twice daily for 9 days, beginning on Day 13 of pregnancy. The largest follicles or cysts in the ovaries of these animals on Days 15, 17, 19, and 22 were incubated for 4 h in the presence of 1) medium alone, 2) 1 mM cAMP, 3) 800 ng/ml A4 with or without cAMP, or 4) 800 ng/ml testosterone with or without cAMP.