Effects of amino acids on insulin release from excised rabbit pancreas.

Abstract

The influence of amino acids, tolbutamide and glucose on the release of insulin from excised rabbit pancreas into Krebs buffer was studied. Glucose stimulated insulin release and a dose response relationship was demonstrated. Tolbutamide stimulated insulin release in the absence of glucose in the buffer. The amino acids arginine, lysine, leucine and histidine when tested in buffer containing either no glucose or glucose 0.5 mg/ml failed to stimulate insulin release. However, when the amino acids were tested in buffer containing glucose1.5 mg/ml or tolbutamide 125 μg/ml, they caused significant enhancement of insulin release. No essential difference of insulin releasing potency was demonstrated among the individual amino acids tested. Epinephrine inhibited insulin release stimulated by glucose and by glucoseamino acid. It is concluded that at least the major effect of amino acids on insulin release is dependent upon the presence of a primary stimulant (e.g., glucose or tolbutamide). (Endocrinology 84: 835,...