Figure 1.

Dexamethasone suppressed apoptotic DNA fragmentation induced by TNF-α and bacterial LPS. (A) Bovine glomerular endothelial cells were incubated for 24 h with 25 ng ml⁻¹ TNF-α and 30 ng ml⁻¹ LPS in the absence or presence of increasing concentrations of dexamethasone. DNA fragmentation was quantitated by the diphenylamine reaction. Data are means±s.e. mean of four separate experiments. ^*P<0.05 (ANOVA and for multiple comparison the data were corrected by Dunn's Method). (B) The formation of oligonucleosomal DNA fragments was assessed by conventional agarose gel electrophoresis. Cells were incubated with vehicle (control), 10 nM dexamethasone (Dex), 25 ng ml⁻¹ TNF-α (TNF-α), 25 ng ml⁻¹ TNF-α/10 nM dexamethasone (TNF-α+Dex), 30 ng ml⁻¹ LPS (LPS), and 30 ng ml⁻¹ LPS/10 nM dexamethasone (LPS+Dex) for 24 h as indicated. The formation of a DNA ladder is a marker of apoptosis rather than necrosis. The results are representative of three independent experiments.