Effects of sevoflurane preconditioning on wnt/GSK3-β/β-catenin signaling pathway during myocardial ischemia-reperfusion injury in rats in vitro

Objective To evaluate the effects of sevoflurane preconditioning on wnt/glycogen synthase kinase-3 beta (GSK-3β)/β-catenin signaling pathway during myocardial ischemia-reperfusion (I/R) injury in rats in vitro. Methods Ault male Wistar rats, weighing 220-280 g, were heparinized and anesthetized with intraperitoneal 3% pentobarbital 30 mg/kg. Their hearts were rapidly excised and perfused in a langendorff apparatus with oxygenated (95% O2-5% CO2) K-H solution at 37 ℃. After 15 min of equilibration, 36 isolated hearts were randomly divided into 3 groups (n=12 each) using a random number table: sham operation group (group S), group I/R and sevoflurane preconditioning group (group SP). After 30 min of equilibration, the hearts were continuously perfused for 150 min in group S. The isolated hearts were subjected to 30 min of ischemia followed by 120 min of reperfusion. In SP group, the hearts were perfused for 15 min with K-H solution containing 2.4% sevoflurane, followed by 5 min washout before reperfusion. At the end of equilibration and 30 min of reperfusion, HR, left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP) and ±dp/dtmax were recorded. The severity of arrhythmias was assessed during reperfusion. At 60 min of reperfusion, 3 hearts in each group were chosen for measurement of expression of wnt3a, phosphor-GSK-3β(p-GSK-3β) and β-catenin (by Western blot). At 120 min of reperfusion, 6 hearts in each group were chosen for determination of myocardial infarct size by TTC staining. Results Compared with group S, HR, LVDP, + dp/dtmax and -dp/dtmax were significantly decreased, and LVEDP was increased at 30 min of reperfusion, arrhythmia scores and the percentage of myocardial infarct size were increased, and the expression of wnt3a, p-GSK-3β and β-catenin was down-regulated in I/R group. Compared with group I/R, HR, LVDP, + dp/dtmax and -dp/dtmax were significantly increased, and LVEDP was decreased at 30 min of reperfusion, arrhythmia scores and the percentage of myocardial infarct size were decreased, and the expression of wnt3a, p-GSK-3β and β-catenin was up-regulated in group SP. Conclusion Sevoflurane preconditioning attenuates myocardial I/R injury by activating wnt/GSK-3β/β-catenin signaling pathway in isolated rat hearts. Key words: Anesthetics, inhalation; Ischemic preconditioning; Myocardial reperfusion injury; Wnt proteins; Glycogen synthase kinase 3; beta catenin