The hypothesis of this project is that adult muscle satellite cells cultured in vitro and implanted into injured myocardium are thought to develop into neomyocardium. Satellite cells will be isolated from adult rat laussimns dorsi muscle and cultured in vitro. To allow confirmation of their presence after implantation into myocardium, an E. coli plasmid pCMVlacZ coding for B-galactosidase and neomycin resistance will be used to label the satellite cells. Transfection will occur by lipofection technique. Prior to implantation, myocardial injury will be inflicted in the same rats which had their muscle explanted by performing a surgical ligature of coronary artery branch. Control, culture medium only, and implant channels will be created into the injured myocardium. The morphology of implanted cells will be analysed microscopically, in addition to functional parameter investigations of whole heart explauts. This technique of cellular eardiomyoplast may present a significant advance in the eure for myocardial infarction.