Cerebral oxygen, glucose, lactate, and pyruvate metabolism in stroke. Therapeutic considerations.

Abstract

Cerebral blood flow, oxygen, glucose, lactate, and pyruvate metabolism were measured in 13 subjects with completed stroke. Cerebral blood flow and oxygen consumption were reduced, glucose consumption and pyruvate production were normal, and lactate production was increased, suggesting a shift from aerobic to anaerobic cerebral glycolysis. To test this hypothesis, cerebral blood flow and oxygen delivery were decreased by hyperventilation and increased by inhalation of 5% CO 2 in air. Hyperventilation decreased cerebral oxygen consumption (CMRO 2 ) and increased cerebral lactate production. Inhalation of 5% CO 2 in air increased cerebral blood flow and oxygen delivery and increased both glucose and oxygen consumption. Relationships between reduction in PaCO 2 and cerebral venous PO 2 and increased cerebral lactate production were found. Increasing cerebral blood flow by 5% CO 2 inhalation improved circulation and oxygen delivery to ischemic cerebral areas and improved oxygen and glucose metabolism in the majority of cases since these procedures do not alter CMRO 2 in normal persons. Intravenous injection of glucose increased cerebral glucose uptake but insulin did not.