摘要:

The anabolic nature of insulin on muscle protein has been recognized since the initial clinical use of insulin therapy in type 1 diabetes abouty sixty years ago, but the exact mechanism whereby insulin effects muscle protein metabolism in human subjects remains unclear. In particular, the effect of insulin on muscle protein synthesis has been debated.In vitrostudies document a stimulatory effect of insulin on muscle protein synthesis, butin vivoresults are conflicting. Everything from decreased muscle protein synthesis to increased muscle protein synthesis in response to insulin has been reported. A recent publication suggests that the response of muscle protein synthesis to insulin is dose dependent, and that only supra-physiological dose of insulin stimulate muscle protein synthesis. On the other hand, some studies show a stimulatory effect of insulin in low doses. It is possible to form a more coherent picture of the effect of insulin if the results from various experiments are expressed in the context of the availability of amino acids. In general, insulin stimulated muscle protein synthesis in studies in which intramuscular amino acid availability was maintained or increased regardless of the dose of insulin. In contrast, insulin was ineffective in stimulating muscle protein synthesis when amino acid availability was allowed to drop, irrespective of the dose of insulin. Thus, whereas insulin has a potential stimulatory effect on human muscle protein synthesis, an adequate availability of amino acids is required for that potential to be expressed in an actual increase in the synthetic rate.

ISSN:1363-1950    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:1363-1950    

出版商:OVID    

年代:2000

数据来源: OVID