Infusion of tumor necrosis factor/cachectin promotes muscle catabolism in the rat. A synergistic effect with interleukin 1.

摘要: To improve our understanding of the metabolic role cytokines in protein wasting, we estimated rates synthesis and degradation muscle liver tissues intact rats treated with several doses recombinant IL 1 and/or tumor necrosis factor (TNF)/cachectin. Protein breakdown were derived vivo from relationship between [14C]leucine distribution tissue dilution reference to circulating leucine. Synthesis was appearance protein-bound free-tissue leucine pools. specifically relate changes tracer metabolism dynamics, separately measured effect these on blood flow different tissues. The increase tissue-free by TNF TNF/IL mixture, but not alone, could be explained a hemodynamic cytokines. Rather, this finding indicated that proteolysis is enhanced synergistically augmented addition 1. Compatible data more prolonged infusions TNF/cachectin combination increased urinary nitrogen excretion. Changes less pronounced than those skeletal consistent net anabolic protein. We conclude exposed systemically sublethal respond increasing decreasing proteolysis, similar observed inflammation cancer.