Administration of Testosterone Is Associated with a Reduced Susceptibility to Myocardial Ischemia

This study investigated the impact of testosterone on myocardial ischemia-reperfusion injury and corresponding intracellular calcium ([Ca2+]i) metabolism. Nonorchiectomized mature male Wistar rats were randomly assigned to placebo, a single dose of testosterone undecanoate, or 5α-dihydrotestosterone. In a further series, orchiectomized rats were treated with placebo. After 2 wk of treatment, the hearts were removed and placed in a Langendorff setup. The isolated, buffer-perfused hearts were subjected to 30 min of no-flow ischemia and 30 min of reperfusion. Recovery of myocardial function was measured by analyzing pre- and postischemic left ventricular (LV) systolic/diastolic pressure and coronary perfusion pressure simultaneously, together with [Ca2+]i handling (aequorin luminescence). Calcium regulatory proteins were analyzed by Western blotting. LV weight/body weight ratio was increased after administration of testosterone vs. orchectomized rats. The recovery of contractile function was improved in test...