Influence of hypothermia on intracellular pH during anoxia

Among the biochemical processes initiated by anoxia or ischemia that play a central role in cellular injury during deprivation is an alteration in cellular hydrogen ion concentration. In this study, the rate of exchange of intracellular hydrogen ion concentration in canine brain was compared with that in liver, using the 5,5-dimethyloxazolidine-2,4-dione method during anoxia at 37 and at 20 degrees C. The intracellular pH of brain decreased more rapidly than it did in liver anoxia at 37 degrees C. The intracellular pH of neither brain nor liver changed substantially during 30 min of anoxia at 20 degrees C. Although the ratio of tissue to plasma water did not change, the calculated extracellular-to-intracellular volume ratio increased during 30 min of anoxia at 37 but not at 20 degrees C.