RESUMO
Objectives To investigate the effect of electric vagal stimulation on the gene expression of injured myocardium from ischemia/reperfusion rat model and explore the involved molecular mechanism.Methods Twenty Sprague Dawley male rats were randomly selected and divided into 2 groups evenly:ischemia/reperfusion group (I/R group),and vagus nerve stimulation group (STM group).The left anterior descending coronary artery (LAD) was ligated and subjected to 30 min of myocardial ischemia followed by 2 h of reperfusion.In addition,10 min before reperfusion,left cervical vagus nerve of STM group was subjected to electronic stimulation at 5 V,2 ms and 1 Hz for 20 min.After 120 min of reperfusion,every group was randomly divided into two parts.One part that myocardium was collected from left ventricle was applied to determine the area of myocardial infarction.The RNA isolated from another part of the ischemic myocardium collected from left ventricle was hybridized to get gene expression profiles and the quality of hybridized RNA from both I/R and STM group was assessed and analyzed.GeneSpring software was applied to screen out the genes,which show significant difference between groups I/R and STM.Real-time polymerase chain reaction (RT-PCR) was applied to analyze the expression of important genes.Results (1)The area of myocardial infarction of STM (25.5 ± 3.9) ％ was significant reduced relative to L/R group (45.5 ± 4.8) ％ (P ＜ 0.05).(2)The expression levels of 186 genes were changed significantly,and analyzed by Gene ontology (GO) software,there were 3 kinds of genes were affected.The upregulated genes were reported to show protective effect on myocardium.The downregulated gene was relative to inflammation.(3)The RT-PCR result confirmed the genechip assay.Conclusions Electric vagal stimulation can reduce myocardial I/R injury in rats.Significant change of the gene expression was detected between groups I/R and STM.The results suggest that activation of cholinergic anti-inflammatory pathway be involved in the mechanism.
RESUMO
Objective To investigate the efficacy of vascular endothelial growth factor (VEGF) gene therapy in coronary occlusion of animal Methods 19 swine underwent left thoracotomy followed by the ligation of left anterior descending coronary artery Constructed pcD 2/hVEGF 121 eukaryotic expression plasmid was directly injected into the swine myocardium RT PCR, immunohistochemistry of VEGF and factor Ⅷ related antigen were used to detect VEGF gene expression and biological effect Coronary angiography was done to evaluate collateral circulation of the occluded artery Results High levels of VEGF mRNA and protein expression were detected There was a significant increase in the number of capillaries when compared with control group Coronary angiography showed better collateral circulation in VEGF group Conclusion Direct injection of pcD 2/hVEGF 121 eukaryotic expression plasmid can transfect the myocardium and express VEGF protein This gene product can increase capillary number and enhance collateral circulation of the occluded coronary