Oxygen consumption and energy state in an in vitro model of rat brain perfused with artificial oxygen carrier

The present study was performed in order to determine the oxygen consumption of a rat brain perfused with an artificial oxygen carrier. Measurements were performed prior to and 2 or 30 min after an ischemic period of 5 min. In addition, the energy-related metabolites were determined. Basal oxygen consumption and energy state were comparable to in vivo conditions. The tissue concentration of the energy metabolites decreased during ischemia and completely recovered during 30 min of reperfusion. The oxygen consumption was higher in the early phase of reperfusion than under pre-ischemic conditions. However, the oxygen consumption in the later phase of reperfusion was lower than the basal consumption. The data demonstrate that the addition of an artificial oxygen carrier to the perfusate provides sufficient amounts of oxygen to the in vitro preparation and that the measurement of the oxygen consumption during the post-ischemic reperfusion is a more sensitive parameter for the detection of emerging deficits than the measurement of the tissue levels of the energy metabolites.