The Effects Of Intravenous Administration Of Human Umbilical Cord Blood Cells (HUCBC) On The Angiogenesis In Rabbits With Acute Myocardial Infarction

Objective: To investigate the effects of intravenous administration of Human Umbilical Cord Blood Cells (HUCBC) on the expression of VEGFmRNA and the angiogenesis in rabbits with acute myocardial infarction.Methods: 45 Chinese rabbits were divided into three groups randomly: Cells transplantation group with 15 rabbits was intravenously administrated with HUCBC labeled with bromodexyuridine(BrdU) at 24h after myocardial infarction; Control group with 15 rabbits was intravenously administrated with saline at 24h after myocardial infarction. the sham operation group with 15 rabbits, not receiving ligation of coronary artery, was intravenously administrated with saline at 24h after operation. Cardiac funtions were performed by echocardiography at 1st week, 2nd week and 4th week after transplantation. The survival of transplanted cells and microvessle density in the myocardium were identified by immunohistochemistry. The expression of VEGF mRNA in the myocardium was examined by RT-PCR.Results: (1) Compared to control group,transplantation of HUCBC improved left ventricular function indexs such as LVFS,LVEF at all 3 examinations; (2) Immunohistochemistry showed that BrdU positive cells were found only in the transplantated rabbits. Compared with control group, there was a significant increase of microvessle density within the boundary of infarcted myocardium in cell transplantation rabbits. (3) Compared with control group, there was an markedly higher level of the expression of VEGF mRNA in the transplantated group.Conclusions: (1) Intravenous administration of HUCBCs obviously improved the heart fuction; (2) The HUCBCs by intravenous administration could migrate into the peri-infarcted area and survive, and increase neovasculation in the peri-infarcted area. (3) The HUCBCs by intravenous transplantation could enhance the expression of VEGFmRNA in the peri-infarcted area. The results suggested that angiogenesis induced by the HUCBCs might be the one of main mechanisms for stem cell transplatation for myocardial infarction.