title: Insulin release in response to vagal stimulation in anaesthetized cats.
abstract: Peripheral and portal plasma insulin concentrations were determined in eviscerated cats before, during and after vagal stimulation. Basal peripheral insulin levels averaged 2.4 ng/ml and portal levels 18 ng/ml. The portal blood flow was recorded continuously, thus enabling the insulin output/min to be calculated. In addition, the total insulin content of the pancreas was determined, which permitted quantitative comparisons of insulin release and pancreatic insulin content to be made. About 2% of the insulin store was released during one hour under basal conditions. Unilateral vagal stimulation with frequencies ranging between 1 and 20 Hz induced an almost immediate release of insulin into the portal vein. Following stimulation with frequencies of 3-4 Hz, the release mechanism was fatigued by a total of 2000-3000 impulses. The insulin output produced by such a supramaximal stimulation averaged 1.5 microgram and constituted about 2% of the total pancreatic insulin content. 15-20 min was needed for the release mechanism to recover.
mesh_terms: D000818:Animals; D002415:Cats; D004558:Electric Stimulation; D007328:Insulin / Q000097:blood*; D007700:Kinetics; D011863:Radioimmunoassay; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology*
chemical_list: D007328:Insulin