Chloral hydrate anesthesia alters cerebral enzymes in the rat. A histochemical study

Cerebral forebrain arterioles and neuropil were analyzed histochemically to determine the effects of chloral hydrate anesthesia on key enzymes of aerobic and anaerobic metabolism, as well as the hexose monophosphate shunt in rats. Significant decreases were observed in cytochrome oxidase, and beta-hydroxybutyrate dehydrogenase in arterioles, while glucose-6-phosphate dehydrogenase and isocitric dehydrogenase showed a significant increase and lactate dehydrogenase showed no significant change. In the neuropil, cytochrome oxidase, isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase showed significant increases following chloral hydrate administration, while beta-hydroxybutyrate dehydrogenase and lactate dehydrogenase showed no significant changes. These data suggest that surgical anesthetic levels of chloral hydrate can impair forebrain metabolism which may lead to altered electrophysiological responses.