Ion leakage is reduced during anoxia in turtle brain: a potential survival strategy

Abstract

The turtle brain maintains ATP levels, ion homeostasis, and some neural function during prolonged anoxia despite significant decreases in the rate of ATP production. To test the hypothesis that reduced ATP production during anoxia was compensated partly by conserving energy through reduced ion leakage, the rate of K+ leakage was measured in normoxic and anoxic turtle brains in which Na(+)-K(+)-adenosinetriphosphatase was inhibited with ouabain. Rates of K+ leakage were significantly lower in brains subjected to 2 h of anoxia than in normoxic brains. These data support the suggestion that reduced ion leakage is an important mechanism for energy conservation during anoxia.