Influence of whole-body mechanical vibration on altitude convulsion threshold

Altitude convulsion threshold was used for determining the maximal hypoxic tolerance of the mouse during whole-body transverse vibration. Elevation of the lung weight-body weight ratio was taken as evidence of lung edema. It was observed that vibration of 8 cps at 2 mm displacement (peak to peak) or 4 cps at 4 mm displacement did not affect the altitude convulsion threshold and the said ratio. On the other hand, vibration of 12 cps at 2 mm displacement, or 8 and 12 cps at 4 mm displacement caused an increase in a altitude convulsion threshold as well as lung edema. The possible mechanism of these changes is discussed.