Fig. 7.

TNF, sphingomyelin, and oxidant signaling. (A) TNF-induced nSMase activity in myotubes, 5 min pretreatment of TNF (6 ng/ml, choline release, n=9), ^⁎P<0.05. (B) Increased oxidant activity in C2C12 myotubes pretreated for 20 min with TNF (6 ng/ml) or C2-ceramide (10 µM). Measured by DCF fluorescence assay, each treatment was applied to 12-wells of cultured myotubes, the 5 brightest myotubes per well were analyzed, each data point is an average of these 5 myotubes (RFU=relative fluorescence units), ^⁎P<0.02 vs. untreated, paired comparison.