Effect of tumor necrosis factor-alpha on skeletal muscle metabolism.

Over the past year, considerable progress has been made in our understanding of biologic actions by which tumor necrosis factor-alpha (TNF-alpha) may influence skeletal muscle metabolism. Reports published during this period highlighted three general actions with metabolic consequences: accelerated catabolism (protein loss, insulin resistance), contractile dysfunction, and disruption of myogenesis. Recent research also indicates that skeletal muscle myocytes synthesize TNF-alpha and that the cytokine functions as an endogenous mediator of muscle adaptation via autocrine/paracrine effects. These advances demonstrate the fundamental importance of TNF-alpha effects on skeletal muscle myocytes and provide a focus for future studies of intracellular mechanism.