The Stimulation of Insulin Secretion in Dogs by Tris (Hydroxymethyl) Aminomethane

Summary Dogs infused with Tris buffer exhibited not only the hypoglycemia reported by others, but also an increase in plasma insulin level as estimated by immunoassay. The induced hyperinsulinemia was much greater in portal vein than in peripheral vein plasma samples. Both hypoglycemia and hyperinsulinemia were much more pronounced when the Tris infused was at pH 10.2 than at pH 7.4. Since Tris molecules are less ionized at higher pH, these findings are in accord with the hypothesis that hypoglycemia induced by Tris is due to this compound penetrating into and inducing release of insulin from the pancreas. The hyperinsulinemia induced by pH 10.2 Tris infusion into the pancreatic artery started later and was more variable than that induced by an equimolar infusion of glucose.