Branched-chain amino and keto acid metabolism in pancreatic islets.
The metabolism of L-leucine in pancreatic islets is reviewed. Regulatory sites may involve the transport and intracellular distribution of L-leucine, its transamination as modulated by the availability of 2-keto acids, the activity of branched-chain 2 keto acid dehydrogenase and the further catabolism of isovaleryl coenzyme A. Emphasis is also placed on the activation of glutamate dehydrogenase by L-leucine, its interference with the utilization of endogenous nutrients and the reciprocal effects of L-leucine and either L-glutamine or L-asparagine upon their respective metabolism. The relevance of L-leucine metabolism to its insulinotropic action is underlined.
D000818:Animals; D001692:Biological Transport; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D007424:Intracellular Fluid / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism*; D007651:Keto Acids / Q000378:metabolism; D007930:Leucine / Q000378:metabolism*; D010084:Oxidation-Reduction; D013347:Subcellular Fractions / Q000378:metabolism
D007651:Keto Acids; C013082:alpha-ketoisocaproic acid; D005969:Glutamate Dehydrogenase; D007930:Leucine