Discrimination between Vascular and Direct Effects on Cerebral Parenchyma of Emopamil
In previous studies the calcium entry blocker emopamil was demonstrated to faster restore high-energy phosphates during the first 5 min of postischemic recirculation in the isolated rat brain perfused at constant pressure but not at constant flow rate. Furthermore, the compound caused lower cortical lactate levels after 30 min of postischemic reperfusion. This effect was also present at constant flow rate perfusion and proved to be independent of the flow rate used. As metabolite determinations were performed in cortical tissue and were compared to global flow rates, the purpose of the present investigation was to evaluate whether intracerebral redistribution phenomena might account for the observed diverging results. Furthermore, the question was posed whether the accelerated decrease in cortical lactate levels was due to enhanced oxidative degradation or to an increased loss into the perfusate.