Effect of halothane on CO2 production from glucose, fructose and pyruvate in rat cerebral cortical slices

Abstract— The effect of halothane on rat cerebral cortical metabolism was studied by measuring ¹⁴CO₂ production from various ¹⁴C]-labelled substrates. Glucose metabolism was depressed by clinically-used concentrations of halothane (0.35 mm ; 1.65 MAC) which did not significantly affect the metabolism of fructose or pyruvate. We concluded that halothane blocked an early step(s) in glycolysis preceding phosphofructokinase. Hexokinase was considered unlikely as the site of blockade, leaving glucose uptake or the glucose phosphate isomerase step as the most likely site(s). Higher concentrations of halothane (0.7 mm ; 3.3 MAC) were required to block the metabolism of fructose or pyruvate to CO₂. This action of halothane was attributed to the known inhibition by halothane of electron transport processes.