The effects of dogfish MSH's and of corticotrophin-like intermediate lobe peptides (CLIP's) on avoidance behavior in rats

Abstract

Recently purified melanocyte-stimulating hormones (MSH's) from dogfish pituitary tissue were tested on extinction of a conditioned avoidance response (CAR). Corticotrophin like intermediate lobe peptides (CLIP's) from dogfish and porcine origin were tested for an effect on avoidance extinction as well. All peptides appeared to delay extinction of the CAR.

The results suggest that the pituitary contains various peptides which influence adaptive behavior. The observation that MSH is more potent in delaying extinction of the CAR then CLIP leads to the conclusion that the behavioral active sequence of the ACTH molecules is located in the N terminal part rather than in the C terminal part of the polypetide.