Effect of Shenfu injectio on insulin resistance in rabbits undergoing cardiopulmonary bypass

Abstract

Objective To investigate the effect of Shenfu injectio on insulin resistance in rabbits undergoing cardiopulmonary bypass (CPB) . Methods Thirty New Zealand white rabbits of both sexes weighing 2.2-2.5 kg were randomly divided into 3 groups (n = 10 each): group I sham operation (group S); group Ⅰ CPB and group Ⅰ CPB + Shenfu injectio (group SFI). In group IE (group SFI) Shenfii injectio 10 ml/kg was injected intraperitoneally (IP) once a day for 2 days and at 30 min before anesthesia. In group Ⅱ and Ⅲ the duration between aortic cross-clamping and unclamping was 60 min. MAP was maintained at 50-60 mm Hg during CPB. The plasma glucose and insulin concentrations were measured immediately after induction of anesthesia (T_1), immediately after aortic cross-clamping (T_2) , and at 5, 35 and 75 min after aortic unclamping (T_3, T_4 , T_5) and insulin resistance index (HOMA-IR) was calculated. The expression of insulin receptor substrate-1 (IRS-1), phosphatidyl-inositol 3 kinase (PI3Kp85) and glucose transporters (CLUT4) in skeletal muscle was detected at 150 min of CPB by immuno-histochemistry. Results Compared with the baseline values at T_1 , plasma glucose and insulin concentrations and HOMA-IR were significantly increased at T_(2-5) in all 3 groups ( P < 0.05) . CPB significantly increased the plasma glucose and insulin concentrations and HOMA-IR at T_(2-5) in group Ⅱ and Ⅲ as compared with group S ( P < 0.05). The expression of PI3Kp85 and GLUT4 in muscle was significantly decreased in group Ⅱ and Ⅲ as compared with group S ( P < 0.05). Shenfu injectio significantly decreased plasma glucose concentration and HOMA-IR and increased plasma insulin concentration in group fD as compared with group Ⅱ . Shenfu injectio significantly attenuated the CPB-induced changes in IRS-1, PI3Kp85 and GLUT4 expression in muscle. Conclusion Shenfu injectio can ameliorate CPB-induced insulin resistance and the mechanism may be related to the up-regulation of the expression of insulin signal transduction molecules in skeletal muscle. Key words: SHENFU DECOCTION; Cardiopulmonary bypass; Insulin resistance