The effects of estradiol and progesterone on spontaneous cytochrome c release: Western blot and the expression of MnSOD in cytosolic and mitochondrial fractions. Cytoplasmic fractions were also extracted at 18 hours from control neutrophils and cells incubated with LPS, estradiol, progesterone, or both (10^-8 g/mL). Cytosolic cytochrome c release was assessed using Western blot analysis. Cytoplasmic and mitochondrial fractions were also stained with MnSOD polyclonal antibody. Each blot represents 1 of 3 separate independent experiments.