IVT CCK-8 is more effective than IV CCK-8 at decreasing meal size in the baboon.
In this study, we compared the effectiveness of intravenous (IV) vs. intraventricular (IVT) cholecystokinin octapeptide (CCK-8) to decrease single meal size over a dose range of 0.1 to 4.0 micrograms/kg in a population of overnight fasted baboons. IV CCK did not decrease meal size significantly at doses of 0.5, 1, and 4 micrograms/kg (84 +/- 22%, 78 +/- 12%, and 89 +/- 33% of paired control meal sizes respectively). IVT CCK significantly decreased single meal size at all doses tested (40 +/- 18%, 26 +/- 10%, 37 +/- 15%, 26 +/- 12%, and 12 +/- 6% of paired control meal sizes at 0.1, 0.25, 0.5, 1, and 2 micrograms/kg respectively). Meal suppression with IVT CCK was significantly greater than that achieved with IV CCK at doses of 1 and 2 micrograms/kg. We conclude that in the baboon, CCK may have a direct effect at the central nervous system to suppress single meal size.
Department of Psychology, University of Washington, Seattle 98195.
D P
DP
Figlewicz
A J
AJ
Sipols
P
P
Green
D
D
Porte
S C
SC
Woods
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects*; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D008297:Male; D010215:Papio / Q000502:physiology*; D012844:Sincalide / Q000008:administration & dosage*
D001786:Blood Glucose; D012844:Sincalide