Effect of open-heart operation involving cardiopulmonary bypass on myocardial endoplasmic reticulum stress

Abstract

Objective To explore the myocardial endoplasmic reticulum stress (ERS) during the open heart surgery involving cardiopulmonary bypass (CPB), and whether the reduced ERS by beating-heart technique played an important role in the myocardial protection. Methods Forty patients with rheumatic heart disease undergoing MVR were randomly divided into 2 groups. The patients in the experimental group received operation on beating-heart, while under arrested heart in the control group. Right atrial myocardial samples were taken before and after CPB. The expressions levels of mRNA and protein of GRP78 and NF-κBp65 were detected using real-time PCR and Western blotting. Results After CPB, the expression levels of mRNA and protein of GRP78 were 2.31±0.44 and 0.096±0.024, those of NF-κBp65 were 2.89±0.93 and 0.129±0.034 respectively in the control group. In the experimental group, the expression levels of mRNA and protein of GRP78 were 1.56±0.29 and 0.061±0.021, and those of NF-κBp65 were 1.73±0.48 and 0.085±0.025. As compared with the baseline values, mRNA and protein levels of GRP78 and NF-κBp65 were increased after CPB. The increasing degrees of GRP78 and NF-κBp65 were significantly lower in the experimental group than in the control group (P=0.001, 0.002; P=0.001, 0.001). Conclusion ERS could be provocated during open-heart operation. The attenuated ERS, through NF-kappaB pathway, may play an important role in myocardial protection by on-pump beating-heart technique. Key words: Open-heart operation involving cardiopulmonary bypass; Beating heart surgery; Endoplasmic reticulum stress; Inflammatory reaction