Long-term Ovariectomy Reduces Tolerance of Rats to Myocardial Ischemia-reperfusion Injury

Background: The harmful impact of ovariectomy on myocardial ischemia-reperfusion (M/IR) injury has been established in the short term. Objectives: In this study, we aimed to investigate long-term effects M/IR injury. Methods: Two methods involving dorsolateral skin incisions were used induce ovariectomized (OVX) rat model. rats divided into 2 groups: Control and OVX (n = 6). At end hearts isolated subjected global ischemia using Langendorff apparatus. Cardiac Function Indices (CFIs) recorded, including left ventricular end-diastolic pressure (LVEDP), peak rates positive (+dp/dt) negative (-dp/dt) changes LV pressure, LV-developed (LVDP). reperfusion period, measure size infarct, levels nitric oxide metabolites (NOx), mRNA expression NO synthase (NOS) enzymes, endothelial (eNOS), neuronal (nNOS), inducible (iNOS). Results: Compared controls, had larger infarct by 51%, higher LVEDP 29%, lower recovery +dp/dt, –dp/dt, LVDP 22%, 35%, respectively. Furthermore, heart tissue, that underwent significantly concentrations nitrate, nitrite, NOx 79%, 82%, 83%, Additionally, these eNOS 38% iNOS 71%. Conclusions: deficiency estrogen increased decreased tissue rats. Imbalanced NOS expressions associated with exacerbated responses