Effects of Oxygen at High Pressure on the Transport of Potassium, Sodium and Glutamate in Guinea Pig Brain Cortex

Abstract

Slices of guinea pig brain cortex were suspended in a medium containing inorganic ions (in concentrations similar to those present in plasma), glucose and glutamate. They were shaken for 90 minutes at 37°C in oxygen, the partial pressure of which was varied from 1 to 11 atm. absolute. Raising the pressure above 4 atm. absolute resulted in the slices losing considerable quantities of potassium. At 6 atm. absolute the slices accumulated considerably less glutamic acid than they did at 1 atm. These findings suggest that brain cells are unable to maintain their normal concentrations of these two substances when exposed to oxygen at high pressure and suggest a possible mechanism for the origin of the disturbances of function in the central nervous system of animals exposed to high pressures of oxygen.