Suppression of neuropeptide Y-elicited eating by adrenalectomy or hypophysectomy: reversal with corticosterone.
Neuropeptide Y (NPY) injected into the paraventricular hypothalamus (PVN) stimulates a robust eating response in the satiated rat. To examine whether the NPY-feeding system interacts with the pituitary-adrenal axis, the eating response to PVN injections of NPY (78 pmol) was tested in adult male rats before and after sham surgery, adrenalectomy (ADX), hypophysectomy (HYPX), and/or corticosterone (CORT) replacement therapy. In unoperated or sham groups, NPY elicited 5.7-8.8 g of food intake in 1 h as compared to 0.4-1.1 g for vehicle-injected animals. In ADX groups, the NPY-elicited response was reduced by 60-71%, to between 2.4 and 2.8 g. Likewise, the average response of the HYPX group was reduced by 69%, to 1.7 g. Corticosterone replacement, via subcutaneous implant of a 100 mg CORT pellet, normalized the NPY-induced feeding response in both the ADX and HYPX groups. These findings suggest that the hypothalamic NPY-feeding system is largely dependent upon circulating CORT and that no other adrenal or pituitary hormone is essential.
Stanley
B G
BG
Rockefeller University, New York, NY 10021.
Lanthier
D
D
Chin
A S
AS
Leibowitz
S F
SF
D000818:Animals; D003345:Corticosterone / Q000378:metabolism / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D008297:Male; D009478:Neuropeptide Y / Q000494:pharmacology* / Q000502:physiology; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D010913:Pituitary-Adrenal System / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains
D009478:Neuropeptide Y; D003345:Corticosterone