Background: Myocardial ischemia is inadequate perfusion due to reduced blood flow. Sudden onset of reperfusion could result with damage to the myocytes that have not been affected during ischemia called ischemia reperfusion (I/R) injury. Extracellular accumulation of H+ ions resulting in tissue acidosis is one of the underlying mechanisms. Inhibition of myocardial H+/K+-ATPase, namely proton pump, may lead to intracellular acidification via decreasing the extracellular H+ transport.
Aim: The aim of this study is to investigate the effects of a proton pump inhibitor pantoprazole in intact rat I/R models.
Materials and methods: A total of 30 adult male Wistar albino rats weighing 200-300 g were studied. Rats were allocated into four groups: sham (n=6), ischemia (n=8), control (n=8), and pantoprazole (n=8). Left anterior descending coronary artery was occluded for 30 minutes and then reperfused for two hours. Pantoprazole was administered via jugular vein at the dose of 9 mg/kg starting from 30 minutes before ischemia, to the first 30 minutes of reperfusion. Haemodynamic parameters were recorded and serum CK-MB levels were measured. After reperfusion, heart was removed for the measurement of myocardial infarct size. Myocardial infarct area was measured using triphenyltetrazolium chloride (TTC) staining technique. Myocardial infarction size were expressed as the percentage of the total left ventricular weight.
Results: Compared with other groups, plasma concentrations of CK-MB at the end of ischemia and reperfusion and myocardial infarct size were significantly lower in pantoprazole group (p < 0.008).
Conclusions: Pantoprazole preconditioning induces delayed cardioprotection in intact rat I/R model, which may be triggered via H+/K+-ATPase ion channels.