BRAIN ENERGY-METABOLISM IN THE ACUTE STAGE OF EXPERIMENTAL SUBARACHNOID HEMORRHAGE - LOCAL CHANGES IN CEREBRAL GLUCOSE-UTILIZATION

An experimental model was used to investigate acute alterations of cer ebral metabolic activity in rats subjected to subarachnoid haemorrhage (SAH). Haemorrhages were produced in anaesthetized animals by injecti ng 0.3 ml of autologous, arterial nonheparinized blood into the cister na magna. Control rats received subarachnoid injections of mock-cerebr ospinal fluid to study the effect of sudden raised intracranial pressu re, or underwent sham operation. Three hours after SAH rats were given an intravenous injection of [C-14]-2-deoxyglucose. Experiments were t erminated by decapitation, and the brains were removed and frozen. Reg ional brain metabolic activity was studied by quantitative autoradiogr aphy. In comparison with sham-operated controls, cerebral metabolic ac tivity was diffusely decreased after SAH. Statistically significant de creases in metabolic rate were observed in 23 of 27 brain regions stud ied. Subarachnoid injections of mock-cerebrospinal fluid also produced depression of cerebral metabolic activity, but quantitatively these c hanges were not as pronounced and diffuse as in SAH rats. The present study shows that a widespread depression bf brain metabolism occurs in the acute stage after experimental SAH and is probably secondary to t he subarachnoid presence of blood itself and/or blood products.