[Reversibility of glucose utilization in focal cerebral ischemia]

Although changes in local cerebral blood flow and glucose metabolism during and following transient "global" ischemia have been discussed, no reports for these changes in transient "focal" ischemia have been made. In the present report we studied reversibility of cerebral blood flow and glucose metabolism after transient "focal" ischemia. Focal ischmia was induced in rat by clipping a left middle cerebral artery by Zen's clip. Local cerebral blood flow (LCBF) and local cerebral glucose utilization (LCGU) were measured by quantitative autoradiography using 14C-iodoantipyrine and 14C-deoxyglucose, respectively. At 2 and 3 hours after clipping, 70% reduction of LCBF was found in the left sensorimotor cortex. At one hour after restoration of blood flow from 2 hours of occlusion LCBF recovered to 70% of controls. At 2 and 3 hours after clipping, LCGU was low in the territories of the left MCA, which were surrounded by zones of high LCGU. Low LCGU may represent a depressed glucose metabolism and high LCGU, anaerobic glycolysis. The abnormal pattern of LCGU seen at 2 hours after occlusion was clearly improved by restoration of blood flow. The results indicate that glucose metabolism might be reversible in the moderate degree of focal cerebral ischemia, and early restoration of blood flow may be beneficial for glucose metabolism.