Effect of gender factors on reduction of ischemia-reperfusion injury by sevoflurane postconditioning in isolated rat cardiomyocytes

Objective To investigate the effect of gender factors on the reduction of ischemia-reperfusion （I/R） injury by sevoflurane postconditioning in isolated rat cardiomyocytes. Methods Sixty 2-month-old SD rats （30 male, 30 female） were used in this study. Male rats were randomly assigned into 2 groups （n = 15 each）：control group （group MC） and sevoflurane postconditioning group （group MS）. Female rats were also randomly assigned into 2 groups （n= 15 each）： control group （group FC） and sevoflurane postconditioning group （group FS）.The rats were anesthetized with intraperitoneal pentobarbital 60 mg/kg. Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃. I/R was produced by 40 min of global ischemia followed by 120 min of reperfusion. Control groups received perfusion with K-H solution saturated with O2 . Sevofiurane postconditioning groups received 10 min of perfusion with K-H solution saturated with 3%sevoflurane and O2 and then 110 min of perfusion with K-H solution saturated with O2 . HR, left ventricular enddiastolic pressure （LVEDP） and left ventricular developed pressure （LVDP） were measured before ischemia and during reperfusion. Coronary effluent was collected at 5 min of reperfusion for determination of LDH activity and infarct size. The total Akt （t-Akt） and phosphorylated Akt （p-Akt） expression in cardiomyocytes was detected. The ratio of p-Akt to t-Akt （p-Akt/t-Akt） was calculated. Results LVDP, p-Akt expression and p-Akt/t-Akt were significantly higher, LVEDP and LDH activity were significantly lower, and the infarct size was smaller in group MS and FC than in group MC （P 〈 0.05）. LVDP was significantly lower, LVEDP and LDH activity were significantly higher, and the infarct size was larger in group FS than in group MS. There was no significant difference in LVDP and LVEDP between group FC and FS （P 〉 0.05）. Conclusion There are gender differences in the reduction of I/R injury by sevoflurane postconditioning in isolated rat cardiomyocyes, the protective effect is stronger in male rats than in female rats, and the differences may be related to the activation of Akt. Key words: Anesthetics,inhalation; Myocardial reperfusion injury; Sex factors