Several of the current techniques for transfer of both olidetected in the nuclei of more than 70% of the myocytes gonucleotide and plasmid DNA into the myocardium are and endothelial cells both in the epicardium and endocarimpaired by low efficiency and toxicity. To improve gene dium. ␤-Gal was expressed in the cytosol of more than transfer techniques, especially into the whole heart, a gene 50% of the myocytes. ␤-Gal expression was demonstrated transfer method involving liposome in conjunction with a by Western blotting analysis at day 3 after transfection and viral envelope (HVJ-liposome) was essayed as an alternacontinued for at least 14 days. No significant histological tive. FITC-labeled oligonucleotide (F-ODN) and the cDNA damage of the myocardium or leakage of CPK were of ␤-galactosidase (␤-gal) were introduced into the myocardetected in the rats transfected by the HVJ-liposome dium by coronary infusion of HVJ-liposome during cardiomethod. These results clearly demonstrate that the hearts plegic arrest of adult Sprague-Dawley rat hearts. Then, were efficiently transfected both by oligonucleotide and transfected heart was ectopically transplanted into another plasmid DNA as a result of coronary infusion of HVJ-liporat abdomen of the same strain to maintain the transfected some during cardioplegic arrest. This thus appears to be heart long enough to allow for protein synthesis. After 3 an efficient method for gene transfer into the whole heart, days of transfection, transfected heart was excised and the providing a new tool for research and therapy for heart efficiency of gene transfection was evaluated. FITC was diseases.