Brain Metabolism During Acclimatization to High Altitude

Abstract

Acclimatization of rats to lowered barometric pressure equivalent to 11,000, 18,000, and 22,000 feet did not alter significantly the levels of the brain constituents. The following fractions were detd.: inorganic P, phosphocreatine, organic P, glycogen, lactic acid, adenylic acid, adenosine diphosphate (ADP), adenosine triphosphate (ATP), hexose diphosphate, glucose-1-phosphate, and diphosphopyridine nucleotide. The hemoglobin rose markedly in rats maintained at 18,000 and 22,000 feet. In rats breathing N for 3 min., the brain ATP, ADP, phosphocreatine, organic P, and glycogen decreased while the inorganic P, lactic acid, and adenylic acid increased correspondingly. The other constituents remained essentially constant. No change in the activity of brain cytochrome oxidase was apparent after acclimatization. The rate of p32 incorporation into brain ATP was unaltered after acclimatization.