The Research On The Relationship Between The Expression Of Glucose Transporter4and The Metabolism Of Glucose In The Transformation Of Rat Myocardial Viability

Objective:To assess the relationship between the expression of Glucose Transporter4（GLUT4） and the metabolism of glucose in the transformation of ratmyocardial viability,and to analyze the mechanisms.Methods:30healthy male SPF SD rats were randomly into two groups:experimentalgroup （n=21） and control group （n=9）.Experimental group was takenisoprenaline hydrochloride by peritoneal injection （5mg.kg-1.day-1） andcontrol group was taken normal saline by peritoneal injection（5mg.kg-1.day-1） for7days. The radioactivity of heart was detected by γradioimmunoassay determinator after the tail vein injection of5.55MBq（150μCi）¹⁸F-FDG.Blood glucose,serum insulin and high-sensitivitycardiac troponin I （hs-cTnI） levels were measured.The expression ofGLUT4in myocardium was measured by immunohistochemistry.Comparativedata between the two groups were statistically analyzed by two-sample ttest，Correlations between the radioactivity of heart and the expressionof GLUT4in myocardium were determined by Pearson correlation analysis.Results:There was no significant difference in blood glucose and serum insulinlevels between the experimental group and control group（t＝-0.991,P＞0.05and t＝-0.208,P＞0.05）.The average value of hs-cTnI ofexperimental group was11.392±1.621ng/ml and the normal control of hs-cTnI was0.052±0.025ng/ml,there was significant difference betweenthe two groups（t＝32.055，P＜0.05）,that indicated myocardial injury inthe experimental group.The value of¹⁸F-FDG uptake in myocardium ofexperimental group was lower than control group （1.687±0.133and2.576±0.285,t＝-8.953,P＜0.05）.The expression of GLUT4in myocardium inischemic region of experimental group, infarcted region of experimentalgroup and control group was significant different, ischemic region ofexperimental group was significant higher than infarcted region ofexperimental group （t＝24.112，P＜0.05）;ischemic region of experimentalgroup was significant higher than control group （t＝-5.619，P＜0.05）;infarcted region of experimental group was significant lower than controlgroup （t＝15.964，P＜0.05）. The value of¹⁸F-FDG uptake in myocardium ofexperimental group was positively correlated with both of the expressionof GLUT4in myocardium in ischemic region of experimental group andexpression of GLUT4in myocardium in infarcted region of experimentalgroup（R2=0.914，P＜0.05and R2=0.922，P＜0.05）. The value of¹⁸F-FDG uptakein myocardium of control group had a positive linear relationship withthe expression of GLUT4in myocardium in control group（R2=0.950，P＜0.05）.Conclusions:In the ischemic myocardium,the value of¹⁸F-FDG uptake is increased viaenhanced the expression of GLUT4,the glycolytic metabolism is increased.In the infarcted myocardium,the value of¹⁸F-FDG uptake is decreased viareduced the expression of GLUT4,the glycolytic metabolism isdecreased.There is a close relationship between GLUT4expression andglucose metabolism after the transformation of rat myocardial viability.