Gastric distension and short-term satiety in the rhesus monkey

Fasted rhesus monkeys given access to a solution of glucose (0.5 kcal/ml) would, within 15 min, consume it to satiety. If, after such a 15-min bout of consumption, the contents of the stomach were removed via an indwelling cannula, the monkeys would again consume glucose in a following 15-min bout. With experiments paired such that gastric contents were either removed or left in place, the total glucose consumption over four successive bouts when the stomach was emptied between bouts was twice that when the contents were undisturbed. Despite this large difference in consumption, the amount of glucose passing through the pylorus to the intestine was not different in the two conditions. Similar results were demonstrated in a nine-bout series of the same design, in a two-bout series in which gastric contents remaining after the first bout were replaced with equivolumetric amounts of 0.15 M NaCl, and in a one-bout experiment in which consumption of glucose followed a 0.15-M NaCl preload equal in volume to the glucose intake in a single bout the preceding day. Since in the stomach-empty and the stomach-distended conditions of each experiment the postpyloric compartments (small intestine, portal, and systemic circulations) were exposed to identical and physiological amounts of glucose, the difference in consumption must be ascribed to the distension of the stomach.