INHIBITION OF SUCROSE INTAKE BY CONTINUOUS CELIAC, SUPERIOR MESENTERIC, AND INTRAVENOUS CCK-8 INFUSIONS

Two experiments compared the potency of continuous infusions of cholec ystokinin octapeptide (CCK-8) for reducing sucrose intake when adminis tered into abdominal arteries or the jugular vein. Adult, male Sprague -Dawley rats received 22-min infusions of saline or several doses of C CK-8. Sucrose was available for 20 min, beginning 2 min after onset of infusions. In the first experiment, intraceliac CCK-8 in doses of 50, 125, and 312 ng produced significant reductions in intake, but no dos e affected intake when administered into the jugular vein. In experime nt 2, only the highest dose, 312 ng, suppressed intake when infused in to the superior mesenteric artery, and jugular infusions were again in effective. Behavioral observations indicated that intra-arterial CCK-8 had no affect on feeding within the first several minutes of test mea ls but accelerated the subsequent decline in incidence of feeding. The se results suggest that receptors involved in cholecystokinin satiety are widely distributed within the gastrointestinal tract.