POST‐ISCHEMIC CHANGES IN CERTAIN METABOLITES FOLLOWING PROLONGED ISCHEMIA IN THE GERBIL CEREBRAL CORTEX

Abstract ‐Eight metabolites were measured in the post‐ischemic period following either 1 or 3 h of unilateral ischemia in the gerbil cerebral cortex. The levels of ATP, P‐creatine, glucose, glycogen and GABA were essentially restored by 1 h after ischemia. In the 3 h ischemic animals. glycogen continued to increase to greater than control values aftcr 5 and 20 h of recirculation. The Icvels of glutamate were unchanged during the ischemic episode, but decreased to 60% of control at Smin and 1 h after either period of ischemia. The concentrations of cyclic AMP, which were 4‐to 5‐fold elevated during ischemia. increased an additional 6‐fold 5 min after recirculation in both groups. Arter 1 h of recovery. the levels were not different from control values. After the 1 h ischemic period, lactate levels recovered between 5 and 20 h of recirculation. In the 3 h ischemic animals. lactate concentrations were still elevated even after 20 h of recirculation. These data suggest that with the exception of lactate. recovery of metabolites is not sevcrely compromiscd by either 1 or 3 h of ischemia. Furthermore, the changes in glycogen. glutamate and cyclic AMP after recirculation suggest that the recovery process is not just a rcversal of the changes observed during ischemia.