The inhibition of tail-pinch-induced food intake by cholecystokinin octapeptides and their fragments.
The effects of intraperitoneally (ip.) and intracerebroventricularly (icv.) administered sulfated and nonsulfated cholecystokinin octapeptide (CCK-8-SE and CCK-8-NS) and their N- and C-terminal fragments on the tail-pinch-induced feeding behavior of rats were investigated. After ip. administration, only CCK-8-SE inhibited tail-pinch-induced food intake. After icv. administration, both CCK-8-SE and CCK-8-NS, in doses of 800 pmole/rat, reduced the amount of food eaten. Of the CCK fragments tested icv., the sulfated N-terminal fragments, the middle portion of the CCK-8-sequence (the CCK-3-6 fragment), and the C-terminal tetrapeptide depressed the food intake of rats during tail-pinch, whereas the C-terminal tripeptide significantly increased it. The results suggest that CCK peptides inhibit tail-pinch-induced feeding by separate mechanisms, depending on the route of administration.
D000818:Animals; D005247:Feeding Behavior / Q000187:drug effects*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D010146:Pain; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D012844:Sincalide / Q000008:administration & dosage / Q000494:pharmacology*
D010446:Peptide Fragments; D012844:Sincalide