AJP - Regulatory, Integrative and Comparative Physiology, Vol 264, Issue 5 852-R856, Copyright © 1993 by American Physiological Society
Cholecystokinin octapeptide decreases food intake in white-crowned sparrows
R. D. Richardson, T. Boswell, S. C. Weatherford, J. C. Wingfield and S. C. Woods
Department of Psychology, University of Washington, Seattle 98195.
White-crowned sparrows maintained on short days (9:15-h light-dark cycle)
were peripherally injected with 1.0, 4.0, and 16 micrograms/kg ip of
cholecystokinin octapeptide (CCK-8). Meal size over the subsequent 30 min
was significantly depressed in a dose-dependent fashion. Water intake was
not affected. The anorexic effect caused by 4.0 micrograms/kg was
attenuated by 100 micrograms/kg of the type-A CCK receptor antagonist
MK-329 but not by 300 micrograms/kg of the type-B CCK receptor antagonist L
365,260, suggesting that CCK-induced suppression of food intake in this
species is mediated by a CCK-A receptor. Administration of both CCK-A and
CCK-B receptor antagonists alone resulted in no change in meal size. These
experiments suggest that white-crowned sparrows, when weight stable,
respond to CCK-8 in a manner comparable with several mammalian species.
