Cerebral Uptake of Glucose and Oxygen in the Cat Brain After Prolonged Ischemia

Abstract

In cats, total cerebral ischemia of one hour's duration was produced by arterial clamping and lowering of the blood pressure. Following ischemia the brains were recirculated with blood for various periods between 30 minutes and six hours. CBF and uptake of O₂ and glucose were determined and correlated with the electrophysiological recovery of the brain. In four of 20 cats recovery was absent because of respiratory or circulatory insufficiency. In 16 cats signs of progressive electrophysiological function returned. These animals exhibited postischemic hyperemia; electrical excitability of the brains recovered within 15 minutes, and the adenylate energy charge returned to more than 95% of the preischemic value within 30 minutes. O₂ uptake was significantly reduced for about one hour, but returned to or above normal as soon as spontaneous ECoG activity began to reappear. Glucose uptake was initially in the normal range until the cerebral glucose stores were replenished, but then followed a time course similar to that of O₂. It is concluded that aerobic glycolysis may return after one hour's ischemia if the brain is adequately resupplied with glucose and O₂.