Figure 3

Inhibitors of ceramide synthesis modulate tumor necrosis factor (TNF)-α effects on myotube sphingolipid content. (A) Total ceramide levels were determined in myotubes treated for 3 days with TNF-α, without or with 100 nmol/l myriocin, 10 μmol/l GW4869, or 1 μmol/l OMS. Results are expressed as a percentage of control value, and are the mean ± SE of 3 to 5 determinations. ++ Different from control: P = 0.02; *different from TNF-α alone: P = 0.05, **:P = 0.02, ***P < 0.001. Mean ± SE control value is 14.7 ± 3.4 pmol ceramide/μg proteins. (B) Total sphingomyelin levels were determined in myotubes treated for 3 days with TNF-α, without or with 100 nmol/l myriocin, 10 μmol/l GW4869, or 1 μmol/l OMS. Results are expressed as a percentage of control value, and are the mean ± SE of 3 to 5 determinations. ++ Different from control: P = 0.002, +++ P < 0.001; *different from TNF-α alone: P = 0.05, **P = 0.02. Mean ± SE control value is 118.8 ± 17.2 pmol sphingomyelin/μg proteins.