Reduction of cell injury in hypoxic cultures of rat myocardial cells by methylprednisolone

Summary An in vitro model to study myocardial cell injury was developed with primary monolayer cultures of rat myocardial cells. Two important conditions associated with myocardial ischemia were simulated by depriving the cultures of oxygen and glucose for a specified period of time. Cellular injury caused by hypoxia and glucose deprivation resulted in significant leakage of lactate dehydrogenase (LDH) from the cells into the culture medium. The cells were not lethally injured by treatments as reflected by a lack of change in cell viability and protein content when compared to controls. Pretreatment of cultures with methylprednisolone for 24 hr provided protection to the cells when challenged by hypoxia and glucose deprivation. Methylprednisolone exhibited a dose-response effect in reducing LDH leakage in cultures, which were subsequently deprived of oxygen and glucose for 4 hr. Similar pretreatment with hydrocortisone had no effect in limiting cellular injury in hypoxic and glucose-deprived cultures. The research was supported by Grant HL 18647 from the National Heart, Lung, and Blood Institute and by a National Chicano Council on Higher Education Post-Doctoral Fellowship awarded to D. Acosta from the Ford Foundation. Additional support was provided to D. Acosta by a Faculty Research Assignment Award from the University of Texas Research Institute.