Intravenous cholecystokinin octapeptide in pigs reduces operant responding for food, water, sucrose solution or radiant heat

Abstract

The effect of intravenous injections of 0 (Saline vehicle), 10, 20 or 40 units of CCK was studied in pigs performing operant responses for food, water, sucrose solution or radiant heat. In hungry pigs working for food, thirsty pigs responding for water, and non-deprived pigs working for sucrose, 20 and 40 units CCK produced significant dose-related decreases in response rates lasting for about 5 min. In pigs responding for 10 sec bursts of infra-red heat at an ambient temperature of 5 degrees C, 40 units CCK significantly reduced the response rate during the 5 min period following injection.