RESUMO
BACKGROUND: Reoxygenation of an ischemic heart causes a decrease in the cardiac function, which is known as reperfusion injury that is associated with an increase in the concentration of reactive oxygen species (ROS). This study examined the effect of the propofol concentration on the generation of ROS during reoxygenation in rat embryonic heart H9c2 cells. METHODS: Cultured H9c2 cells were examined in the following sequences: Prehypoxic, Hypoxic and Reoxygenation period. Each period required 60 minutes. The cells were exposed to propofol at the beginning of the prehypoxic period. Thirty minutes later, DCFH-DA (dichlorofluorescin diacetate) 10 micrometer was added to detect the ROS. The propofol concentrations used were 0, 5, 25, 50, 250 micrometer in the first experiment and 0, 1, 2, 3, 4, 5 micrometer in the second experiment. The ROS level was estimated using a fluorometer at 5-minute intervals from 5 to 60 minutes after reoxygenation. RESULTS: When the propofol concentrations was > 5 micrometer, the ROS levels were significantly lower than those of the untreated group (P0) (P 5 micrometer inhibited ROS production over the whole period, and even 1micrometer showed some inhibition of ROS.