Effect of anesthesia and-or hypothermia on cerebral free amino acids in young rats.

Abstract

AbstractThe whole brain content of glutamic acid significantly decreased in unanesthetized and anesthetized (pentobarbital sodium. 20 mg/kg) 10‐day‐old rats during 90 min hypothermia at 23°C, but not in rats kept equally long at 15°C. The concentration of glutamic acid increased during rewarming to 37°C after 90 min at 23 or 15°C. The concentration of aspartic acid significantly increased during rewarming after 90 min at 23 or 15°C. Rats anesthetized for 10 or 90 min at 37°C had increased cerebral concentrations of leucine and methionine, but the concentrations were significantly lower in rats kept for 90 min at 23°C. During rewarming after 90 min at 23 or 15°C the levels of leucine and methionine increased. The content of ethanolamine phosphate was significantly elevated in rats kept anesthetized for 90 min at 37, 23, or 15°C. An elevated ethanolamine phosphate concentration was found also in unanesthetized rats kept for 90 min at 15°C. Only minor alterations were found in the concentrations of glutamine, glutathione, γ‐aminobutyric acid, taurine, alanine, ethanolamine, glycine, and serine.