AJP - Regulatory, Integrative and Comparative Physiology, Vol 267, Issue 6 1496-R1502, Copyright © 1994 by American Physiological Society
Cholecystokinin reduces sucrose palatability in rats: evidence in support of a satiety effect
L. A. Eckel and K. P. Ossenkopp
Neuroscience Program, University of Western Ontario, London, Canada.
To investigate the hypothesis that peripherally administered
cholecystokinin (CCK) reduces food intake by the production of aversive
internal cues, we examined the effects of the sulfated, octapeptide form of
CCK on taste reactivity responses to oral sucrose infusions in male rats
implanted with intraoral cannulas. After injection of CCK (4, 8, or 16
micrograms/kg ip) or 0.15 M saline (1 ml/kg ip), a series of brief (30 s)
intraoral infusions of a 0.30 M sucrose solution was administered at 2-min
intervals for 10 min. All doses of CCK were found to significantly decrease
ingestive responding during the first and subsequent sucrose infusions
without promoting a significant increase in aversive responses relative to
controls. The lack of a gradual, conditioned shift in taste reactivity
responses, from an ingestive to an aversive pattern (which is typically
observed after LiCl administration), suggests that the production of
nausea-like aversive internal cues was likely not responsible for the
observed CCK-induced alterations in taste reactivity responses. It appears
that the unconditioned, satiogenic effects of CCK contributed to the
selective reduction in ingestive responses observed in the present study.
