Alpha-melanocyte stimulating hormone and ghrelin: central interaction in feeding control.
Alpha-melanocyte stimulating hormone (alpha-MSH) and ghrelin play significant yet opposite roles in the regulation of feeding: alpha-MSH inhibits, whereas ghrelin stimulates consumption. The two peptidergic systems may interact in the process of food intake control. A single report published thus far has shown that a synthetic agonist of the melanocortin receptors, MTII, injected in the hypothalamic paraventricular nucleus (PVN) decreases feeding generated by ghrelin. We found that very low doses of alpha-MSH and MTII administered ICV significantly reduced ghrelin-dependent hyperphagia. However, an endogenous molecule, alpha-MSH, infused in the PVN did not exert an inhibitory effect on ghrelin-induced consumption, whereas the effective dose of PVN MTII exceeded that necessary to decrease short-term deprivation-induced feeding. We conclude that it is likely that in feeding regulation alpha-MSH and ghrelin "interact" at the central nervous system level, but the involvement of the PVN in this interaction appears questionable.
Olszewski
Pawel K
PK
Minnesota Obesity Center, VA Medical Center, Minneapolis, MN 55417, USA.
Bomberg
Eric M
EM
Grace
Martha K
MK
Levine
Allen S
AS
D000818:Animals; D005247:Feeding Behavior / Q000187:drug effects*; D054439:Ghrelin / Q000008:administration & dosage / Q000494:pharmacology*; D007276:Injections, Intraventricular; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D000521:alpha-MSH / Q000494:pharmacology*
D054439:Ghrelin; D000521:alpha-MSH