4-Hydroxyisoleucine: A Novel Amino Acid Potentiator of insulin Secretion:

摘要

We report the characterization of a new insulinotropic compound, 4-hydroxyisoleucine. This amino acid has been extracted and purified form fenugreek seeds, which are known in traditional medicine for their antidiabetic properties. 4-Hydroxyisoleucine increases glucose-induced insulin release, in the concentration range of 100 μmol/l to 1 mmol/1, through a direct effect on isolated islets of Langerhans from both rats and humans. The stimulating effect of 4-hydroxyisoleucine was strictly glucose dependent; indeed, ineffective at low (3 mmol/1) or basal (5 mmol/1) glucose concentra- tions, the amino acid potentiated the insulin secretion induced by supranormal 96.6-16.7 mmol/1) concentra- tions of glucose.