Effect of increased pressures of oxygen, nitrogen, and helium on activity of a Na-K-Mg ATPase of beef brain.

Increased pressure of O2, N2,or He exert inhibitory or stimulatory effects on activity of Na-K-Mg ATPase obtained from beef brain cortex. Oxygen at 2 ATA and N2 at 4 ATA exert significant inhibitory effects whereas 3 & 4 ATA O2, 1-3 ATA N2 exert significant stimulatory effects. Effects of He on ATPase activity are qualitatively similar to those of N2. The effects of the gases are not qualitatively altered by the presence or absence of ATP. A pressure compensated analysis reveals that at the same pressures, O2 and N2 exert different effects of ATPase activity.