| Objective: To investigate the effects of bone marrow mesenchymal stem cells (MSCs) transplantation via different routes on cardiac function,myocardial infarct size,capillary density of acute myocardial infarction(AMI) rats, and study whether intravenous transplantation combined with intramyocardial injection has better effects than any one of the two ways.Methods:①Allogeneic male Sprague-Dawley(SD) rats, weighing 80~100g, were sacrificed after intraperitoneal anesthesia. Bone marrow cells were extracted from the tibias and femurs of rats and were placed in culture medium with 10% fetal bovine serum (FBS) under sterile conditions. Nonadherent cells were removed by replacing the culture medium continuously.Once cultures became 80% confluent, adherent cells were detached and subsequently passaged. The fourth generation MSCs were collected and sterile 4,6-diamidino-2-phenylindole (DAPI) (final concentration 50 mg/L) solution was added to the culture medium, incubated at 37℃for 30 minutes. One hour before transplantation,the collected MSCs were centrifuged, rinsed six times in phosphate buffer saline to remove all unbound DAPI and resuspended in serum-free culture medium (MSCs final concentration 2.5×107 /ml).②90 clean male SD rats, body weight (200±20) g, were randomly divided into group A (intravenous transplantation group), group B (intravenous transplantation control group), group C (intramyocardial transplantation group), group D (intramyocardial transplantation control group), group E (united transplantation group) and group F (united transplantation control group), 15 rats in each group. AMI was created by occluding the left anterior descending artery (LAD) in SD rats.The labeled MSCs (5×106 cells/ 200ul) were injected to rats through the tail vein 24 hours after AMI (group A), MSCs (5×106 cells/ 200ul) were injected via epicardium for group C 1 week after AMI, MSCs (5×106 cells/ 200ul) were injected via the tail vein and epicardium at 24 hours and 1 week respectively after AMI for group E and culture medium of the same volume without FBS was transfused to control groups B,D and F.③Four weeks after AMI, the cardiac function was evaluated and rats were killed to observe the DAPI positive cells in heart, liver, spleen, kidney, lungs.The myocardial infarct size and capillary density was calculated after pathology research.Results:①Two rats of groups D and F respectively died while the rest of rats survived to the end of the experiment.②Compared with that of groups B,D and F,the myocardial infarct size and left ventricular end-diastolic pressure (LVEDP) decreased,the capillary density,left ventricular systolic pressure (LVSP) , left ventricular maximum rate of pressure rise and fall(±dp/dtmax) increased significantly in groups A,C and E(P<0.05).③There was no significant difference in groups A,C and E at the aspect of myocardial infarct size(P>0.05).Compared with that of groups A and C, LVEDP decreased, LVSP,±dp/ dtmax,capillary density increased more significantly in group E (P <0.05). But no significant difference was found between groups A and C at the aspect of LVEDP, LVSP,±dp/ dtmax,capillary density(P>0.05).④Many DAPI positive cells could be found in infarcted myocardium of groups A ,C and E , but were not found in liver,spleen,kidney and lungs. There were no tumor and thrombosis in heart, liver,spleen, kidney and lungs of all rats.Conclusion:Our results demonstrated that MSCs transplantation via vein,myocardium or both can all improve cardiac function and increase capillary density of AMI rats,but intravenous transplantation combined with intramyocardial injection has better effects than any one of the two ways, no significant difference was found between intravenous and intramyocardial transplantation. MSCs transplantation via vein,myocardium or both can decrease myocardial infarct size of AMI rats,but united transplantation has no better effects than any one of the two ways.
|
PDF Full Text Request