OBJECTIVETo observe the ultrastructure changes of cerebral cortex neuron and endothelial cell in hypoxia preconditioning mice and the effects of Tongxinluo (TXL, Chinese traditional medilihe) on them.

METHODSMice were randomly divided into 4 groups: control group, hypoxia group, hypoxia preconditioning (HP) group and Tongxinluo (TXL) group. The hypoxia preconditioning mice were exposed by repetitive hypoxia for 5 runs. The animal's tolerance time of each hypoxia run was recorded. The ultrastructure change of cerebral neuron and endothelial cell were studied by electron microscope.

RESULTSThe hypoxic tolerance time in HP and TXL groups were significantly increased run by run. Compared with HP group, the tolerance time of TXL group were increased in every run. The ultrastructure of cerebral neuron and endothelial cell in hypoxia group changed obviously, mitochondrion and endoplasmic reticulum destroyed. However they were slighter in HP group than those in hypoxia group. The change in TXL group had no obvious differentce with control group and were slighter than those in HP group.

CONCLUSIONHypoxia preconditioning shows that organism has a strong self-repairing ability. Tongxinluo self-repairing; could increase self-repairing ability and adaptive ability of mice to hypoxia obviously.