Fig. 5.

17β-Estradiol abrogates H₂O₂-induced caspase-3 activation in C2C12 skeletal muscle cells. C2C12 cells were treated as follows. Control vehicle isopropanol alone, E2 10⁻⁸ M 17β-estradiol for 8 h, H₂O₂ 0.5 mM H₂O₂ during 8 h, H₂O₂+ E2 10⁻⁸ M 17β-estradiol for 45 min followed by 0.5 mM H₂O₂ during 8 h. Cell lysate proteins (25 μg) from each condition were fractionated by SDS-PAGE and then immunoblotted with anticaspase-3 antibody as described in “Materials and methods”. The band detected represents uncleaved (inactive) caspase-3 (35 kDa). Actin levels were measured as protein loading controls. Experiments were repeated at least three times with essentially identical results. Representative immunoblots and densitometric analysis are shown