OBJECTIVE: To determine the nature of bioactive FSH secretion in anovulatory women with polycystic ovary syndrome (PCOS) and its modulation by luteal levels of E2 and P. DESIGN: Interventional and observational study. SETTING: Academic clinical research center. PATIENT(S): Five patients with PCOS. INTERVENTION(S): Treatment for 21 days with luteal levels of E2 and P. MAIN OUTCOME MEASURES: Serum levels of immunoreactive LH, immunoreactive FSH, bioreactive FSH, and the FSH isoform distribution pattern. Blood was sampled frequently and GnRH testing was done on day 0 (before treatment), days 10 and 20 (during treatment), and day 28 (7 days after treatment). RESULT(S): Treatment with E2 and P suppressed circulating immunoreactive LH and immunoreactive FSH but not bioreactive FSH. Anovulatory women with PCOS showed a predominantly acidic pattern of FSH isoform distribution. Treatment with E2 and P shifted the distribution profile of FSH isoforms to the less acidic. After cessation of E2-P treatment, FSH reverted to its pretreatment pattern of distribution. CONCLUSION(S): Resumption of follicular growth after luteal replacement of E2 and P in anovulatory women with PCOS may be related to the reduction in the elevated LH/FSH ratio and accompanying changes in the FSH signal.
OBJECTIVE: To determine the nature of bioactive FSH secretion in anovulatory women with polycystic ovary syndrome (PCOS) and its modulation by luteal levels of E2 and P. DESIGN: Interventional and observational study. SETTING: Academic clinical research center. PATIENT(S): Five patients with PCOS. INTERVENTION(S): Treatment for 21 days with luteal levels of E2 and P. MAIN OUTCOME MEASURES: Serum levels of immunoreactive LH, immunoreactive FSH, bioreactive FSH, and the FSH isoform distribution pattern. Blood was sampled frequently and GnRH testing was done on day 0 (before treatment), days 10 and 20 (during treatment), and day 28 (7 days after treatment). RESULT(S): Treatment with E2 and P suppressed circulating immunoreactive LH and immunoreactive FSH but not bioreactive FSH. Anovulatory women with PCOS showed a predominantly acidic pattern of FSH isoform distribution. Treatment with E2 and P shifted the distribution profile of FSH isoforms to the less acidic. After cessation of E2-P treatment, FSH reverted to its pretreatment pattern of distribution. CONCLUSION(S): Resumption of follicular growth after luteal replacement of E2 and P in anovulatory women with PCOS may be related to the reduction in the elevated LH/FSH ratio and accompanying changes in the FSH signal.