Objective: To investigate the changes in glucose transporter-4(Glut-4) mRNA expression in skeletal muscle before and after the thoracic operation and to observe the changes in Glut-4 mRNA expression by preoperative infusion of glucose. Methods: Twelve cases of elective thoracic operation were randomly divided into two groups, namely ordinary group Ⅰ and glucose infusion group Ⅱ. One gram of intercostal muscle was taken while thorax being opened and closed from patients under general anesthesia. Total RNA of the muscle cells was extracted by TRIzol one-step assay. Reverse transcription-competitive polymerase chain reaction (RT-PCR) was used to determine the Glut-4 mRNA amplification products with β-actin mRNA as an internal control. The Glut-4 mRNA expression was expressed by targeted gene /β-actin ×100%. The plasma glucose and insulin levels were determined at the same time.Results: Glut-4 mRNA expression was significantly reduced(P<0.05) and plasma glucose level increased (P<0.05), while thorax was being closed as compared with those while being opened. However, Glut-4 mRNA expression in glucose infusion group Ⅱ was significantly higher than ordinary group Ⅰ (P<0.01) and plasma glucose level in group Ⅱ was lower than group Ⅰ(P<0.05) when thorax was being closed. Conclusion: The results indicate that the synthesis of Glut-4 is suppressed by the surgical stress of thoracic operation under general anesthesia. We found that preoperative infusion glucose can increase Glut-4 mRNA expression at the same surgical stress and relieve postoperative insulin resistance.
