RESUMO
Objective:To evaluate the effect of sevoflurane on Ca 2+ transporter expression in cardiomyocytes during right ventricular remodeling in rats with pulmonary arterial hypertension. Methods:Twenty-four clean-grade healthy male Sprague-Dawley rats, aged 8-10 weeks, weighing 200-250 g, were divided into 4 groups ( n=6 each) by the random number table method: control group (CM group), sevoflurane group (CS group), monocrotaline group (M group) and sevoflurane + monocrotaline group (S group). Monocrotaline 60 mg/kg was intraperitoneally injected in group M and group S, and monocrotaline lysate was intraperitoneally injected in group CM. The rats in S and CS groups inhaled 2.5% sevoflurane for 1 h, twice a week, at an interval of 3 days starting from the first day after injection of monocrotaline. Pulmonary artery acceleration time and pulmonary artery ejection time were measured by transthoracic echocardiography at 6 weeks after monocrotaline injection. The chest was exposed under 3% sevoflurane anesthesia, the heart was perfused, and the pulmonary artery branch and right ventricular myocardial tissues were retained. The wall thickness of pulmonary arterioles and cross-section area of right ventricular cardiomyocytes were observed by HE staining. The expression of Ca 2+ transporter in right ventricular cardiomyocytes was detected by Western blot. Results:Compared with CM group, the ratio of pulmonary artery acceleration time to pulmonary artery ejection time was significantly decreased, the cross-section area of right ventricular cardiomyocytes was increased, the wall thickness of pulmonary arteriole was increased, the expression of type 1 sodium-calcium exchange and inositol triphosphate receptor was up-regulated, and the expression of voltage-dependent L-type calcium channel α1C subunit, type 2 ryanodine receptor, sarcoplasmic reticulum calcium pump 2α and proteinphilin-2 was down-regulated in M group ( P<0.01). Compared with group M, the ratio of pulmonary artery acceleration time to pulmonary artery ejection time was significantly increased, the cross-section area of right ventricular cardiomyocytes was decreased, the wall thickness of pulmonary arteriole was decreased, the expression of type 1 sodium-calcium exchange and inositol triphosphate receptor was down-regulated, and the expression of voltage-dependent L-type calcium channel α1C subunit, type 2 ryanodine receptor, sarcoplasmic reticulum calcium pump 2α and proteinphilin-2 was up-regulated in group S ( P<0.01). Conclusions:The mechanism by which sevoflurane improves right ventricular remodeling is related to regulating the expression of Ca 2+ transporter in cardiomyocytes of rats with pulmonary arterial hypertension.