Intraventricular CCK inhibits food intake and gastric emptying in baboons.
To evaluate the role of cholecystokinin (CCK) as a physiological regulator of meal size and gastric emptying in the baboon, we measured plasma CCK bioactivity during 30-min meals alone and after intravenous or intraventricular infusions of CCK COOH-terminal octapeptide (CCK-8). Both intravenous (2 micrograms/kg) and intraventricular (1 microgram/kg) CCK-8 administration resulted in plasma CCK elevations comparable with normal prandial CCK levels: peak plasma levels were 4.1 +/- 0.9, 7.1 +/- 1.1, and 4.9 +/- 2.2 pM for pooled intravenous and intraventricular control, intravenous, and intraventricular conditions. Also, both treatments appeared to reduce gastric emptying as indicated by a significant suppression of postprandial plasma insulin and glucose levels. However, only intraventricular CCK reliably reduced meal size (percent of control meal size was 91 +/- 5% or 43 +/- 19% with intravenous or intraventricular CCK). We conclude that circulating endogenous CCK is a potent postprandial endocrine regulator of gastric emptying. However, the ability of CCK to decrease meal size may require direct interaction with the central nervous system.
Figlewicz
D P
DP
Department of Psychology, University of Washington, Seattle 98195.
Sipols
A J
AJ
Porte
D
D
Woods
S C
SC
Liddle
R A
RA
D000818:Animals; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D002766:Cholecystokinin / Q000097:blood*; D005746:Gastric Emptying / Q000187:drug effects*; D007262:Infusions, Intravenous; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D010215:Papio; D012016:Reference Values; D012527:Satiation / Q000187:drug effects*; D012844:Sincalide / Q000008:administration & dosage / Q000494:pharmacology*
D002766:Cholecystokinin; D012844:Sincalide