OXYGEN-CONSUMPTION AND ENERGY-STATE IN AN IN-VITRO MODEL OF RAT-BRAINPERFUSED WITH ARTIFICIAL OXYGEN CARRIER

The present study was performed in order to determine the oxygen consu mption of a rat brain perfused with an artificial oxygen carrier. Meas urements were performed prior to and 2 or 30 min after an ischemic per iod of 5 min. In addition, the energy-related metabolites were determi ned. Basal oxygen consumption and energy state were comparable to in v ivo conditions. The tissue concentration of the energy metabolites dec reased during ischemia and completely recovered during 30 min of reper fusion. The oxygen consumption was higher in the early phase of reperf usion than under pre-ischemic conditions. However, the oxygen consumpt ion in the later phase of reperfusion was lower than the basal consump tion. The data demonstrate that the addition of an artificial oxygen c arrier to the perfusate provides sufficient amounts of oxygen to the i n vitro preparation and that the measurement of the oxygen consumption during the postischemic reperfusion is a more sensitive parameter for the detection of emerging deficits than the measurement of the tissue levels of the energy metabolites.