Preabsorptive insulin release and hypoglycemia in rats.
Peripheral blood glucose and immunologically reactive insulin levels were determined in freely moving normal rats which were submitted either to a free oral glucose load or to a gastric administration of the glucose load. Identical determinations were performed in ventromedial hypothalamic nucleus-(VMH) lesioned and vagotomized rats after the same oral intake. It was demonstrated that: 1) a free oral glucose intake was immediately followed by two peaks of insulun release and a resultant decrease in blood glucose; 2) a gastric glucose load resulted in a single peak of insulin release and the concomitant decline in blood glucose; 3) the recorded blood glucose level was the resultant of the insulin-induced hypoglycemia and the postabsorptive hyperglycemia; and 4) the responses were largely exaggerated in VMH-lesioned rats and abolished by vagotomy. It is concluded that the early prandial insulin release reflexly induced by food-related stimuli temporarily enhances the metabolic conditions which provoke feeding.
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose; D005260:Female; D005947:Glucose / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology; D007031:Hypothalamus / Q000502:physiology; D007263:Infusions, Parenteral; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D051381:Rats; D012439:Saccharin / Q000494:pharmacology; D014630:Vagus Nerve / Q000502:physiology
D001786:Blood Glucose; D007328:Insulin; D012439:Saccharin; D005947:Glucose