α-Melanocyte stimulating hormone and ghrelin: Central interaction in feeding control

α-Melanocyte stimulating hormone (α-MSH) and ghrelin play significant yet opposite roles in the regulation of feeding: α-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 α-MSH and MTII administered ICV significantly reduced ghrelin-dependent hyperphagia. However, an endogenous molecule, α-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 α-MSH and ghrelin "interact" at the central nervous system level, but the involvement of the PVN in this interaction appears questionable.