Figure 1.

Estrogen maintains thiol antioxidant system in rat bone marrow. (a and b) Ovariectomy (ovx) decreased while 17-β estradiol (βE₂) (10 μg/kg) restored glutathione (nmol/mg protein) and glutathione reductase (mU/mg protein) in bone marrow (r, reduced glutathione; o, oxidized glutathione). (c and d) Ovariectomy suppressed thioredoxin (nmol/mg protein) and thioredoxin reductase (mU/mg protein) in bone marrow, while 17-β estradiol normalized both. (e) 17-α estradiol (αE₂) was without significant effect on glutathione levels. Thiol levels and enzymes were also measured in liver and spleen and did not differ significantly between groups. *P < 0.05 versus all other groups. Data expressed as mean ± SEM; n = 6 per group. These experiments were repeated twice in mice and similarly showed significant changes in the levels of antioxidant defense components in bone marrow after ovariectomy, which were normalized by 17-β estradiol.