Adult stem cells, particularly the side population (SP) cells from bone marrow, can regenerate ischemic cardiac muscle and vascular endothelium. In this study, SP cells were transplanted into lethally irradiated mice with induced ischemia, and they migrated to the heart, differentiated into cardiomyocytes and endothelial cells, and contributed to tissue repair. Donor-derived cardiomyocytes were found in the peri-infarct region, identified by lacZ expression and absence of CD45. Endothelial cells were identified by lacZ and Flt-1 expression. SP cells were shown to have cardiomyogenic potential and could be used as a therapeutic strategy for myocardial infarction. The study also demonstrated that SP cells can regenerate cardiac muscle and blood vessels in ischemic tissue. SP cells were purified from Rosa26 transgenic mice and characterized for their ability to regenerate cardiac myofibers and blood vessels. The study found that SP cells could differentiate into cardiomyocytes and endothelial cells, contributing to tissue repair. The results suggest that hematopoietic stem cells may be a potential source for cardiac regeneration. The study also showed that SP cells can integrate into the heart and contribute to the formation of functional tissue. The findings highlight the potential of SP cells in regenerating cardiac tissue and suggest that they could be used in future therapeutic strategies for heart disease.Adult stem cells, particularly the side population (SP) cells from bone marrow, can regenerate ischemic cardiac muscle and vascular endothelium. In this study, SP cells were transplanted into lethally irradiated mice with induced ischemia, and they migrated to the heart, differentiated into cardiomyocytes and endothelial cells, and contributed to tissue repair. Donor-derived cardiomyocytes were found in the peri-infarct region, identified by lacZ expression and absence of CD45. Endothelial cells were identified by lacZ and Flt-1 expression. SP cells were shown to have cardiomyogenic potential and could be used as a therapeutic strategy for myocardial infarction. The study also demonstrated that SP cells can regenerate cardiac muscle and blood vessels in ischemic tissue. SP cells were purified from Rosa26 transgenic mice and characterized for their ability to regenerate cardiac myofibers and blood vessels. The study found that SP cells could differentiate into cardiomyocytes and endothelial cells, contributing to tissue repair. The results suggest that hematopoietic stem cells may be a potential source for cardiac regeneration. The study also showed that SP cells can integrate into the heart and contribute to the formation of functional tissue. The findings highlight the potential of SP cells in regenerating cardiac tissue and suggest that they could be used in future therapeutic strategies for heart disease.