Fig. 7.

Inflammatory and oxidative stress is increased in old ovx cardiac myocytes. A, Graph summarizes IL-6 and TNF-α levels in the plasma of old rats with and without E₂ replacement. n = 6–11 animals per group. Subsequent studies focused on the isolated cardiac myocytes. B, Graph summarizes the relative mRNA expression of IL-6 and TNF-α in isolated myocytes from old ovx and old ovx + E₂ pellet rats treated with or without 100 nm E₂ pretreatment in vitro. Cytokine expression was normalized to GAPDH. n = 5 animals and plates per group. ^&, P < 0.05 vs. all other groups. C, Graph summarizes the increase in oxidative stress after treating myocytes from old ovx and old ovx + E₂ pellet rats with 100 μm H₂O₂. A subset of cardiac myocytes were pretreated with 5 and 100 nm E₂ for 6 h before insult with H₂O₂. n = 3 animals and 9 plates per group. *, P < 0.05 vs. ctl; ^#, P < 0.05 vs. ctl and identical group in old ovx. D, Representative Westerns and a graph summarizing the expression of catalase, Cu/Zn-SOD, and Mn-SOD, basally and with 100 nm E₂ treatment for 24 h. Blots were normalized to GAPDH and to old ovx. Graph summarizing the results are shown to the right. n = 4–5 animals and plates per group.