Contrasting effects of Org 2766 and alpha-MSH on social and exploratory behavior in the rat.
Intraperitoneal injection of Org 2766 (0.01-0.4 microgram/kg) produced a dose-related increase in the number of social contacts and in the time spent in active social interaction by pairs of male rats tested in arenas with which they were familiar, but had little effect when the rats were tested in unfamiliar arenas. The increased social interaction was not accompanied by any change in motor activity. In contrast, alpha-MSH (20-200 microgram/kg) decreased the time spent in active social dose-related. Both peptides reduced exploratory head-dipping only at high doses (4-8 microgram/kg for Org 2766 and 200 microgram/kg for alpha-MSH); this change was not accompanied by a reduction in motor activity.
D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D005106:Exploratory Behavior / Q000187:drug effects*; D007398:Interpersonal Relations; D008297:Male; D009074:Melanocyte-Stimulating Hormones / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D012919:Social Behavior
D010446:Peptide Fragments; C013765:Org 2766; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones