Acute Cerebral Ischaemia: Concurrent Changes in Cerebral Blood Flow, Energy Metabolites, pH, and Lactate Measured with Hydrogen Clearance and ³¹P and ¹H Nuclear Magnetic Resonance Spectroscopy. II. Changes during Ischaemia

Abstract

CBF has been measured with the hydrogen clearance technique in the two cerebral hemispheres of the gerbil under halothane anaesthesia. This has been correlated with changes in local pH, tissue lactate, and phosphorus energy metabolites measured in the same animals with 1 H and 31 P nuclear magnetic resonance spectroscopy. We demonstrate a threshold flow value for the metabolic changes associated with energy failure at a level similar to the values previously reported for electrical failure and tissue water accumulation, but higher than that associated with breakdown of extracellular potassium homeostasis.