Effects of α-ketocarboxylic acids and 4-pentenoic acid on insulin secretion from the perfused rat pancreas

Pyruvic acid, α-ketobutyric acid, α-ketovaleric acid, α-ketooctanoic acid, α-ketononanoic acid, α-ketoisovaleric acid, α-ketoglutaric acid, α-ketoadipic acid, hydroxypyruvic acid, and 4-pentenoic acid did not induce significant insulin secretion from the perfused rat pancreas, β-phenyl-pyruvic acid and α-keto-β-methylvaleric acid induced only minimal insulin secretion from the perfused rat pancreas which was characterized by a monophasic secretory pattern. Both α-ketocaproic acid and α-ketoisocaproic acid were potent insulin secretagogues which induced a biphasic insulin secretory pattern comparable to the secretory pattern in response to glucose. The insulin secretory potency of this group of chemically related α-ketoacids is discussed.