Palatability and preabsorptive insulin release.

The purpose of these experiments was to determine whether the level of orally-triggered and vagally-mediated preabsorptive insulin release was related to the degree of food palatability as measured by the amount of food necessary to produce satiation. Rats were habituated to a feeding schedule of five meals per day. During a test meal they were presented with one of 3 forms of their regular diet: unaltered, sweetened with Sucaryl sodium or adulterated with quinine hydrochloride. From 1.5 min preceding the meal to 19.5 min later, blood was continuously drawn via a chronic intravenous catheter. Blood was collected for regular intervals and immunoreactive insulin levels were determined. During the test meals, the rats ate 3, 4.9 and 1.5 g of the three diets, respectively. Within the first 3 min following meal onset, they exhibited a peak insulin release of 47, 65 and 25 microU/ml, respectively. Since this early insulin response disappeared long before the end of the meal, it was suggested that the palatability-dependent amount eaten could be affected by the palatability-modulated preabsorptive insulin release.