Previous studies indicate that the menstrual cycles of older reproductive age women are characterized by a selective elevation of FSH associated with early development and ovulation of a dominant follicle. Several intraovarian hormones and growth factors have been identified that appear to serve ...

Previous studies have reported that the monotropic rise in FSH in older women is associated with decreased inhibin B and/or A levels and increased levels of activin A. Whereas most investigators have found decreased follicular-phase inhibin B, the roles of inhibin A and activin A as modulators of ...

BACKGROUND: Serum FSH elevations and decreases in inhibin B have been consistently demonstrated in the early follicular phase of cycles in women of advanced reproductive age. However, secretory products of the dominant follicle (estradiol and inhibin A) in the serum of older ovulatory women are ...

OBJECTIVE: To assess the pituitary responsiveness to GnRH stimulation of premenopausal women relative to age. DESIGN: Older and younger reproductive-age women underwent the GnRH stimulation test in the early follicular phase of the menstrual cycle. SETTING: Female subjects in an academic research ...

Luteal phase deficiency is usually a problem of inadequate progesterone production associated with inadequate ovarian follicular development. The hypothesis that luteal phase deficiency results from an abnormal secretion pattern of luteinizing hormone (LH) was tested in these women. To this end, ...

Serum inhibin levels rise markedly during the luteal phase of the human menstrual cycle and are closely correlated with serum progesterone (P) levels, suggesting that the corpus luteum (CL) secretes inhibin. While FSH is the major regulator of inhibin secretion by the granulosa cells, the control ...

The recurrent deficiency of progesterone (P) secretion by the corpus luteum has been associated with infertility and habitual abortion and given the clinical diagnosis of luteal phase deficiency (LPD). There is evidence that both follicular and luteal phase abnormalities can result in LPD cycles. ...

Inhibin is a gonadal glycoprotein believed to be important in the regulation of pituitary FSH secretion and/or to function as a paracrine factor within the ovary and testis. We studied serum levels of inhibin, oestradiol (E2), progesterone (P), FSH and LH during the periovulatory interval in order ...

The gonadotropin secretion pattern in normal reproductive age women (n = 5) was evaluated for the presence of a circadian rhythm. The women volunteered for a series of 24-h admissions in different phases of their menstrual cycles (early follicular, late follicular, and midluteal). Plasma LH and FSH ...

Luteal phase deficiency (LPD) is a reproductive disorder associated with infertility and spontaneous abortion. This study was undertaken to determine whether LPD might be related to an abnormal pattern of gonadotropin secretion. We tested this hypothesis by evaluating the pattern of pulsatile LH ...