Rupture LH SURGE dissociation of cumulus mass resumption of meiosis Increase blood flow Edema shift in steroid production Stigma formation progesterone collagenase Rupture plasminogen activating factor PGE lysosome activity PGF contractions Egg Release

Duration of the LH Surge LH surge of <14 hours: No change in oocyte and granulosa cells. No support of CL LH surge of <24 hours: Resulted in oocyte meiosis. No support of CL. LH surge of 34 to 48 hours: Resulted in oocyte maturation and CL support. Zelinski-Wooten et al. J Clin Endocrinol Metab 1991 Zelinski-Wooten et al. J Clin Endocrinol Metab 1992

Summary and Conclusions Based on studies in hypophysectomized animals and women with hypogonadotropic hypogonadism, it is clear today that steroidogenesis is mainly supported by the synergistic action of FSH and LH

Summary and Conclusions FSH is the primary hormone in the process of follicle recruitment and selection of the dominant follicle.

Summary and Conclusions Human corpus luteum can be ‘rescued’ and can be function normally after 7 days of deprivation from gonadotropin stimulation in patients with hypogonadotropic hypogonadism.

The Role of LH in Follicular Development Zeev Shoham, M.D. Department of Obstetrics and Gynecology, Kaplan Hospital, Rehovot, Israel rec-hFSH