Effect of tumor necrosis factor alpha on electrically induced calcium transients elicited in C sub(2)C sub(12) skeletal myotubes

Diseases involving chronic inflammation can lead to prolonged exposure of skeletal muscle to inflammatory cytokines such as tumor necrosis factor alpha (TNF alpha ), which may contribute to the skeletal muscle weakness seen in these conditions. In this study we examined the effect of a prolonged exposure to TNF alpha on intracellular Ca super(2+) transients elicited in skeletal C sub(2)C sub(12) myotubes. A 48-h exposure to TNF alpha (10 ng/mL) significantly reduced the peaks, time to peak, and rate of Ca super(2+) decay of electrically induced Ca super(2+) transients elicited in C sub(2)C sub(12) skeletal myotubes. TNF alpha exposure had no significant effect on the resting Ca super(2+) levels. The results of this study indicate that prolonged exposure to TNF alpha decreases sarcoplasmic reticulum Ca super(2+) release in cultured skeletal muscle cells. This altered Ca super(2+) release could contribute to the muscle weakness found in conditions involving chronic inflammation. Muscle Nerve, 2006