Study on the hyperresponsiveness of pituitary FSH to GnRH 6 weeks after delivery.
We investigated the mechanism underlying the hyperresponsiveness of pituitary FSH to GnRH stimulation in puerperal women 6 weeks after delivery. No pulse of LH during the 3-hour sampling period was observed in all of 4 puerperal women studied on day 42 postpartum, while each of 5 eumenorrheic women on day 8 or 9 of the normal cycle had one or two pulses of LH in the 3-hour sampling period. In puerperal women on day 42 postpartum, the mean basal level of serum FSH was slightly, but not significantly higher than that in eumenorrheic women on day 8 or 9 of the normal cycle, but the mean basal levels of serum LH and estradiol were significantly lower than those in eumenorrheic women. The response of serum FSH to GnRH stimulation was significantly and 2-fold higher in puerperal women on day 42 postpartum than in eumenorrheic women on day 8 or 9 of the normal cycle, but there was no difference in the response of serum LH to GnRH between the two groups. These results suggest that the hyperresponsiveness of pituitary FSH to GnRH stimulation in puerperal women on day 42 postpartum may result from the slower frequency of GnRH secretion.
D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D007986:Luteinizing Hormone / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D049590:Postpartum Period / Q000502:physiology*; D011247:Pregnancy; D013268:Stimulation, Chemical
D006728:Hormones; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone