Concentration of hypoxanthine in both cerebrospinal fluid and brain tissue increases under intensive hypoxia only.

The relationships between the concentrations of glycogen, glucose, lactate, adenosine triphosphate (ATP) and hypoxanthine in the brain tissue, and the hypoxanthine and lactate concentration in cerebrospinal fluid and blood were examined after exposure of rats to hypoxia. The animals (1 and 10 days old) were exposed to hypobaric hypoxia for 1-12 h, pO2 11.3 kPa (mild), pO2 8.