Estrogen alters the effects of neuropeptide-Y on luteinizing hormone and follicle-stimulating hormone release in female rats at the level of the anterior pituitary gland.
In recent years, several studies have shown that neuropeptide-Y (NPY) is involved in the control of LH secretion. We determined the effects of estrogen on NPY-induced LH and FSH release in the absence or presence of LH-releasing hormone (LHRH) at the level of the anterior pituitary gland (APG). Adult female rats were ovariectomized. Fifteen to 20 days later, they were given a blank or estrogen-filled capsule subdermally and killed 17-19 h later. APG cells were isolated and cultured for 3 days in medium containing 12.5% rat serum collected at death from the same rats used to make the respective APG cell pools. The cells were then challenged for 3 h with vehicle, NPY (10(-12)-10(-6) M), LHRH (10(-9)-10(-6) M), or combinations of NPY (10(-9)-10(-7) M) and LHRH (10(-9) M). LHRH stimulated LH and FSH release from nonestrogen and estrogen-primed cells. NPY at 6.7 x 10(-8)-10(-6) M increased (P < 0.05) LH release and at 10(-6) M increased (P < 0.05) FSH release from estrogen-primed cells, but was without effect on nonestrogen-primed cells. In contrast, NPY at 10(-9)-10(-7) M potentiated the action of LHRH (10(-9) M) to increase the release of LH and FSH from nonestrogen-primed cells, but was without potentiating effects in cultures of estrogen-primed cells. The results demonstrate that 1) NPY can release LH and FSH by a direct action on estrogen-primed APG cells; and 2) NPY can potentiate the action of LHRH to increase the release of LH and FSH by a direct action on nonestrogen-primed APG cells.
Woller
M J
MJ
Department of Cell Biology and Neuroscience, University of South Carolina School of Medicine, Columbia 29208.
Campbell
G T
GT
Liu
L
L
Steigerwalt
R W
RW
Blake
C A
CA
D000818:Animals; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000378:metabolism*; D009478:Neuropeptide Y / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D004967:Estrogens; D009478:Neuropeptide Y; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone