Cardioprotection of hydralazine against myocardial ischemia/reperfusion injury in rats

This study aimed to investigate whether hydralazine could reduce cardiac ischemia/reperfusion (I/R) injury in rats. Anesthetized male Sprague–Dawley rats underwent myocardial I/R injury. Saline, hydralazine (HYD, 10–30 mg/kg) was administered intraperitoneally 10 min before reperfusion. After 30 min of ischemia and 24 h of reperfusion, the myocardial infarct size was determined using TTC staining. Heart function and oxidative stress were determined through biochemical assay and DHE staining. HE staining was used for histopathological evaluation. Additionally, the cardiomyocytes apoptosis and protein expression of PI3K-Akt-eNOS pathway marker were detected by TUNEL and Western blotting. The serum levels of malonaldehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) and reactive oxygen species were significantly elevated in cardiac I/R group, but the superoxide dismutase (SOD) level was suppressed. However, intraperitoneal pretreatment with hydralazine at a dose of 10–30 mg/kg before cardiac I/R significantly limited the increase in CK-MB, LDH, oxidative stress, inflammatory factors, histological damage and apoptosis in the hearts. In addition, hydralazine also increased p-PI3K, p-AKT, p-eNOS expression and decreased Cleaved Caspase-3, Cleaved Caspase-9 expression in the hearts. Our results suggest that the cardioprotective effect of hydralazine against I/R injury might be a cooperation of the inhibition of oxidative stress, inflammatory response, apoptosis with the motivation of eNOS phosphorylation via activating the PI3K/AKT signal pathway.