Differential effects of melanocortin peptides on ingestive behaviour in rats: evidence against the involvement of MC(3) receptor in the regulation of food intake.
The pro-opiomelanocortin-derived peptides decrease food intake possibly via MC4 receptor. In this study we compared the effects of alpha-melanocyte-stimulating hormone (MSH), beta-MSH and gamma(1)-MSH (0.2, 1.0 and 5.0 microg, i.c.v.) on food intake. alpha-MSH and beta-MSH inhibited spontaneous food intake in a dose dependent manner, whereas the gamma(1)-MSH did not. alpha-MSH and beta-MSH but not gamma(1)-MSH (all 5.0 microg, i.c.v.) inhibited fasting-induced food intake about 50%. None of the three peptides inhibited fluid consumption in water-deprived (24 h) rats. It is suggested that MC(3) receptor, activated selectively by gamma(1)-MSH, is not involved in the regulation of food intake.
Kask
A
A
Department of Pharmacology, Faculty of Medicine, University of Tartu, Ravila 19, 50411, Tartu, Estonia. ants.kask@ut.ee
Rägo
L
L
Wikberg
J E
JE
Schiöth
H B
HB
D000818:Animals; D004435:Eating / Q000187:drug effects* / Q000502:physiology*; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D044104:Receptor, Melanocortin, Type 3; D018043:Receptors, Corticotropin / Q000187:drug effects* / Q000378:metabolism*; D013997:Time Factors; D000521:alpha-MSH / Q000378:metabolism* / Q000494:pharmacology*; D019824:beta-MSH / Q000378:metabolism* / Q000494:pharmacology*; D019825:gamma-MSH / Q000378:metabolism* / Q000494:pharmacology*
D044104:Receptor, Melanocortin, Type 3; D018043:Receptors, Corticotropin; D019824:beta-MSH; D019825:gamma-MSH; D000521:alpha-MSH