Experimental Study Of Tetramethylpyrazine For Endothelial Protection And Prevention Of Restenosis After Coronary Artery Bypass Graft

To explore the role of tetramethylpyrazine for endothelial protection and prevention of restenosis after CABG, ITA were grafted to LAD based on the establishment of experimental coronary artery LAD stenosis and EC injury model in canine. All dog抯 proximal LAD were clamped more than 70% by operation, to establish a experimental coronary artery LAD stenosis and EC injury model. 1 hour after this, ITA were anastomosed to distal LAD with 損ump?or 搊ff pump?methods. tetramethylpyrazine (4Omg/kgld) was given in vein daily and during operation ( starting 48 hours before operation and continuing for 2 weeks after successful procedure). We measured the changes of several EC-derived factor and observed the changes of hA and LAD near anastomosis through common and electronic scanning microscope. The main results as followed. 1 Analysis of the changes of several EC-derived factor showed, experimental coronary artery LAD stenosis and EC injury model were successful made, Endothelial function was seriously damaged when proximal LAD were clamped more than 70%.While the dogs could live on for their big circumflex artery. 2 Compared with control group, Nitrate/Nitrite, 6-keto-PGF1 ~ significantly increased and TXB2,ET-l reduced in tetramethylpyrazine group. This reflected that tetramethylpyrazine could restrained EC-derived contracting factors and stimulated EC-derived relaxing factors increasing. 4 3 The vascular structure of LAD and hA of tetramethylpyrazine抯 group has significant difference with control group after CABG, We discovered that ITA and LAD near anastomosis had less inflammation, without thrombosis, and no structural change of EC, SMC, myocardium through common and electronic microscope. We concluded, tetramethylpyrazine has potential role of endothelial protection and prevention of restenosis after CABG. Tetramethylpyrazine restrained injury of EC and inhibited the development of a chain reactions after injury of EC, therefore restrained vascular inflammation, thrombosis and structural change of EC, SMC, myocardium, prevented restenosis after CABG.