CCK inhibits real and sham feeding in gastric vagotomized rats

We tested both sham feeding and real feeding in gastric vagotomized rats equipped with chronic gastric cannulas, either without pretest food deprivation or after 18 hr food deprivation. In each condition, 0.3-4 micrograms/kg CCK inhibited food intake similarly in control and vagotomized rats. Behavioral observations indicated the presence of normal postprandial satiety after CCK. We then tested real feeding in noncannulated rats after either total abdominal vagotomy, gastric vagotomy, or control operation. Doses of 0.5-4 micrograms/kg CCK had no effect on food intake after total vagotomy, but again inhibited feeding with equal potency in gastric vagotomized and control rats. The inhibitory effect of 6 micrograms/kg CCK was attenuated but not blocked by total vagotomy. Finally, we tested rats with gastric cannulas after gastric plus celiac vagotomy. CCK also inhibited both real and sham feeding after this lesion. These data confirm previous findings that abdominal vagal fibers mediate the satiety effect of moderate intraperitoneal doses of CCK, but fail to support the hypothesis that gastric branch fibers are the necessary vagal contribution.