A quantitative study of the insulin release induced by vagal stimulation in anesthetized cats

Insulin was released by vagal stimulation in anesthetized and eviscerated cats. The plasma insulin concentration and blood flow in the portal vein were determined concomitantly and the insulin output was calculated. Stimulation of either the right or the left cervical vagus released the same amount of insulin, whereas bilateral stimulation released twice as much. Following a stimulation that depleted the "vagally-releasable pool", a recovery period of 15--20 min was needed before the same maximal output could be obtained again. With shorter interstimulatory periods the amounts of insulin released were reduced. When less than 2--3 00 impulses were applied during a stimulation period, the amount of insulin released per impulse was constant. Atropine (0.2--2 mg/kg) did not reduce the vagally-induced insulin release.