Postpyloric regulation of gastric emptying in rhesus monkeys

Saline (0.9% NaCl) empties rapidly and exponentially from the stomach of the rhesus monkey, but glucose solutions empty at a calorie-constant rate of 0.4 kcal/min. By means of indwelling intragastric and intraduodenal cannulae we can demonstrate an inhibition on the delivery of saline from the stomach provoked by glucose placed beyond the pylorus. The inhibition varies directly with the glucose calories in the intestine and averages 2.5 min/kcal. That these two results (0.4 kcal/min and 2.5 min/kcal) are reciprocals suggests a feedback inhibition on the gastric emptying of nutrients arising from beyond the pylorus and adequate to explain the rate of glucose delivery to the intestine. A control theory description of gastric emptying that includes such feedback regulation can be derived from these data to explain the different gastric emptying patterns of nutrients and nonnutrient solutions. These patterns give this visceral system a precision in its management of nutrients that can provide information crucial to preabsorptive satiety.