Antagonism of central and peripheral anorectic effects of caerulein by L-364,718

The reduction in food intake induced by i.p. injections of the cholecystokinin (CCK) analogue caerulein was antagonised by a low dose (0.25 mumol/kg s.c.) of the selective CCK antagonist L-364,718. To block the anorectic effect of centrally administered caerulein a dose of 25 mumol/kg of L-364,718 was required, demonstrating that central CCK receptors can be blocked effectively in the rat by choosing appropriate doses of L-364,718.