Evidence for Abnormal Granulosa Cell Responsiveness to Follicle-Stimulating Hormone in Women with Polycystic Ovary Syndrome

Abstract

Women with polycystic ovary syndrome (PCOS) undergoing ovulation induction appear to be extremely sensitive to gonadotropin stimulation and at increased risk for ovarian hyperstimulation syndrome. To determine granulosa cell responsiveness to recombinant human FSH (r-hFSH), dose-response studies were conducted in 16 individual PCOS patients and 7 normal women. Each subject received an iv injection of r-hFSH at doses of 0, 37.5, 75, or 150 IU in a randomized fashion on four separate occasions. Blood samples were obtained at frequent intervals before and for 24 h after r-hFSH administration for measurement of gonadotropins and steroid hormones. Our results showed that administration of r-hFSH produced instantaneous and equivalent dose-related increases in serum FSH in PCOS and normal women, which were followed by similar exponential decreases to baseline levels within 24 h in both groups. In PCOS subjects, the peak mean incremental response of serum estradiol (E(2)) to 150 IU of r-hFSH was 1.8-fold greater (P < 0.0001) and considerably accelerated compared with that found in normal women. In contrast, E(2) responses to 37.5 IU and 75 IU were similar between groups. Regression analysis of maximal E(2) concentrations in response to r-hFSH in each individual subject revealed that the slope of the linear trend line in the group of women with PCOS (r = 0.82) was significantly greater (P < 0.01) than that of normal controls (r = 0.71). The time-course of response revealed that in PCOS women, increases of E(2) were not sustained, compared with those of normal controls, because peak concentrations were followed by an estimated 40% decrement in circulating levels, whereas E(2) levels in normal women persisted for 24 h after reaching maximal values. These findings indicate that women with PCOS exhibit a significantly greater capacity for E(2) production in response to iv r-hFSH, compared with normal women. In PCOS, E(2) production was relatively transient because after peak concentrations a marked decline was detected at each dose, unlike normal women who exhibited persistent elevations of E(2) for up to 24 h. That this distinction was dose-dependent supports the concept of an FSH dose-response threshold, beyond which PCOS but not normal women are susceptible to ovarian hyperresponsiveness.

Follicular hyperandrogenism downregulates aromatase in luteinized granulosa cells in polycystic ovary syndrome women

“…It activates FSH receptors (FSHRs) in granulosa cells of antral follicles leading to the transcription of aromatase (CYP19), a key enzyme that catalyzes the conversion of androgens to estrogens (Payne & Hales 2004, Stocco 2008, which is required for follicle maturation (Chen et al 2012). In PCOS, the expression of FSHR in granulosa cells appears to be up-regulated (Catteau-Jonard et al 2008), which is believed to be responsible for the observed hyperresponsiveness of PCOS granulosa cells to FSH both in vitro and in vivo (Erickson et al 1992, Mason et al 1994, Coffler et al 2003. Although FSH hypersensitivity accelerates estrogen production, PCOS women were found unable to sustain their estrogen level (Coffler et al 2003).…”

“…In PCOS, the expression of FSHR in granulosa cells appears to be up-regulated (Catteau-Jonard et al 2008), which is believed to be responsible for the observed hyperresponsiveness of PCOS granulosa cells to FSH both in vitro and in vivo (Erickson et al 1992, Mason et al 1994, Coffler et al 2003. Although FSH hypersensitivity accelerates estrogen production, PCOS women were found unable to sustain their estrogen level (Coffler et al 2003).…”

Polycystic Ovary Syndrome in Adolescence

“…They are excessively responsive to FSH, particularly at high dosage. In part this is caused by a larger cohort of follicles, in part because of intrinsic granulosa cell dysfunction [33]. This accounts for the tendency of women with PCOS to develop the dangerous ovarian hyperstimulation syndrome during fertility treatment.…”

Aromatase P450 activity in the natural menstrual cycle and during controlled ovarian stimulation

“…Известно, что у пациентов с СПЯ экспрес-сия ФСГ-рецепторов в клетках гранулезы по-вышена [57,58], что может являться причи-ной гиперчувствительности клеток гранулезы к экзогенному ФСГ [59]. Введение экзогенного ФСГ женщинам с СПЯ приводит к более вы-соким пиковым значениям уровня Э2 в крови и более резкому снижению после достижения пиковой концентрации по сравнению с женщи-нами без СПЯ [59].…”

“…Введение экзогенного ФСГ женщинам с СПЯ приводит к более вы-соким пиковым значениям уровня Э2 в крови и более резкому снижению после достижения пиковой концентрации по сравнению с женщи-нами без СПЯ [59]. Имеются различия в актив-ности ароматазы лютеинизированных клеток гранулезы, полученных при трансвагинальной пункции фолликулов более 18 мм, у пациенток с СПЯ по сравнению с пациентками без СПЯ.…”