Effect of leucine and metabolites of branched chain amino acids on protein turnover in heart.

摘要: Leucine, but not isoleucine or valine, inhibited protein degradation and accelerated synthesis in hearts perfused with buffer that contained glucose (15 mM) normal plasma levels of other amino acids, except for the branched chain compounds. Products leucine, isoleucine, valine metabolism also stimulated synthesis. These compounds included transamination decarboxylation products, as well acetate, acetoacetate, propionate. In some, all instances, inhibition acceleration were accompanied by an increase intracellular leucine. When insulin was added to perfusate, rate reduced 40%, addition leucine ineffective presence hormone. Insulin, (2 a mixture acids at increased latency cathepsin D containing glucose. A combination more than either substance alone. studies indicate variety substrates are oxidized citric acid cycle involved regulation turnover heart muscle.