Effect of +Gz Acceleration on Intracranial Pressure in Rabbits

摘要

Changes of intracranial pressure (ICP) under different G levels and onset rates were investigated in rabbits. Six anesthetized New Zealand rabbits were placed in a prostrate position on the animal centrifuge, and exposed to +3,5,7 Gz (onset rate, 1 G/s) and 0.1,1,3 G/s onset rate (G level, +5Gz) at random, each for 15 s with 15 min rest period between each centrifuge run. The ICp were measured usign thei ntubation of lateral ventricles of the brain. Teh reuslts showed that, ICP decreased from control level of 0.66+-0.13 kPa to -3.22+-1.16 kPa, -5.81+-1.23 kPa and -8.34+-2.39 kPa, respectively, during +3, +5 and +7 Gz exposures. There was a negative linear correlation between ICP and +Gz level, and a positive linear correlation between the change rate of ICP (d(ICP)/dt) and onset rate. ICP increased temporarily immediately after +Gz exposure, then returned to normal progressively. It is suggested that the large, rapid shifts in ICP following +Gz exposure may be an important component in the overalll mechanisms of G-LOC. The ICP increase with the increasing of +Gz level, whereas d(ICP)/dt increase with the increasing of onset rate.