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

SUMMARY 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, in air. Hyperventilation decreased cerebral oxygen consumption (CMRO2) and increased cerebral lactate production. Inhalation of 5% CO2 in air increased cerebral blood flow and oxygen delivery and increased both glucose and oxygen consumption. Relationships between reduction in PaCO2 and cerebral venous P02 and increased cerebral lactate production were found. Increasing cerebral blood flow by 5% CO2 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 CMRO2 in normal persons. Intravenous injection of glucose increased cerebral glucose uptake but insulin did not. Additional Indexing Words: Stroke treatment Cerebral met Cerebral isehemia Five per cent CO2 plus air Cerebral glucose consumption Cer I N A previous study, it was adduced from indirect evidence that, in occlusive cerebro-vascular disease, cerebral anaerobic glycolysis was increased." In the present study, measurements of cerebral lactate and pyruvate production were added in a series of patients with cerebrovascular disease to ascertain directly whether or not cerebral anaerobic glycolysis is increased in such cases by ischem-ic hypoxia. The question was tested further and Toyoda are Fellows of the Michigan Heart Association. tabolism Cerebral vasodilator agents Cerebral anaerobic glycolysis Cerebral oxygen consumption rebral lactate production by increasing and decreasing cerebral blood flow by the use of carbon dioxide inhalation and hyperventilation to note whether either procedure would improve or enhance cere-bral anaerobic glycolysis if present. The question is a practical one since it is relevant as to I whether or not agents which dilate cerebral vessels (such as the inhalation of mixtures of carbon dioxide in air or the oral or intravenous administration of papaverine) are rational forms of treatment in occlusive cerebrovascu-lar disease.2-7 Some have questioned whether carbon dioxide or other cerebral vasodilator agents may divert blood from ischemic areas by lowering the cerebral vascular resistance in surrounding areas of normal brain.34 Others hold the opposite point of view and consider that increasing cerebral blood flow may enhance the blood flow to …