Gonadotrophin regulation in the lactating rat.
Post-partum lactation in the rat is associated with follicular quiescence and an attenuation of gonadotrophin secretion. The present study demonstrates that the lactating rat responds to exogenous LH-releasing hormone (LH-RH) in a manner similar to dioestrous rats. Oestrogen priming increases the LH and FSH response to LH-RH to a smaller degree in ovariectomized, lactating, than in non-lactating, ovariectomized rats. Pituitary LH levels throughout lactation did not seem to be related LH-RH-induced LH release. A diminished post-castration rise in both LH and FSH, and a diminished positive feedback response to oestrogen administration were also observed and may indicate a disruption of gonadotrophin regulation at both the hypothalamic and the pituitary level.
D000818:Animals; D002369:Castration; D004031:Diestrus; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007031:Hypothalamus / Q000502:physiology; D007774:Lactation; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D010902:Pituitary Gland / Q000502:physiology; D011247:Pregnancy; D011359:Proestrus; D051381:Rats
D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone