Intraperitoneal injections of nanogram CCK-8 doses inhibit feeding in rats.
The satiating effect of intraperitoneal injections of synthetic cholecystokinin octapeptide (CCK-8) was tested in non-deprived and 17 h-deprived male and female Sprague-Dawley rats that were maintained on pelleted diet and offered evaporated milk test meals. At the midpoint of the 12-h diurnal period, 40-160 ng/kg CCK-8 elicited a dose-related decrease in meal size. At midnight, CCK-8's threshold for inhibiting feeding was increased to 80-160 ng/kg in nondeprived and deprived rats, respectively. These doses are 25-50 times less than typically required to significantly decrease food intake after intraperitoneal injection. No CCK-8 dose stimulated nocturnal feeding and no consistent sex difference was observed in CCK-8's effect. Intraperitoneal injection of ng amounts of CCK-8 may mimic a paracrine action of endogenous gut cholecystokinin to signal satiety.
Canova
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Columbia University.
Geary
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D000818:Animals; D002940:Circadian Rhythm; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005260:Female; D005508:Food Deprivation / Q000502:physiology*; D007274:Injections, Intraperitoneal; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012527:Satiation / Q000187:drug effects*; D012727:Sex Characteristics; D012844:Sincalide / Q000008:administration & dosage / Q000494:pharmacology*
D012844:Sincalide