| PURPOSE:Our experiment aim to the discusses the protection mechanism in the development of cerebral ischemia by observing the changes of neuronal nitric oxide synthase (nNOS) and insulin-like growth factor- II (IGF- II ) immunocytochemical reactivity neurons in some cerebral nucleus, the ultrastructure changing of neuron in cerebral cortex and the effect of used Salvia miltiorrhiza compound.METHOD:12 SD rats were divided randomly into 4 groups, each contained 18 rats. The control group was only separate the bilateral carotid artery. The other 3 groups were first established bilateral carotid artery ligation (2VO) cerebral ischemia rats, and then were separately with 2VO group, 2VO+NS group and 2VO+DS group. At the end of 8, 16 and 24 weeks, the equal number of rats in every group was sacrificed (n=6 each time). The number of nNOS positive neurons in Acb, SI and PVN were counted and then quantitatively analyzed. Qualitative analysis of IGF- II positive neurons and ultrastructure changing in the cerebrum cortex neurons.RESULTS:(1) The number of nNOS positive neurons in Acb of 2VO and 2VO+NS groups significantly decreased at 8 weeks after ischemia; At ischemia 16 weeks still remain low level and have the significant difference compare to the control group, but till ischemia 24 weeks it have raised to the normal level; in the whole course of ischemia (within 24 weeks), the number of nNOS positive neurons of 2VO+DS groups have no changing but always higher to the 2VO and 2VO+NS groups, and have the significant difference compare to the control group.(2) The number of nNOS positive neurons in S 1 of all 3 ischemia group ( 2VO, 2VO+NS and 2VO+DS group) get to a higher level in ischemia 8 weeks; But decreased to the normal level in ischemia 16weeks, although the number of nNOS positive neurons in SI of 2VO+DS group significantly still higher to the control group, but there have no significant difference.(3) In the whole experiment period, the number of nNOS positive neurons in PVN of the control group has no changing. From Sweeks to 24weeks after ischemia, the number of nNOS positive neurons in PVN of the 2VO, 2VO+NS and 2VO+DS groups increasing significantly, and have no significant difference in each other. But compare to the control group, there have significant difference. And have no changing with developing of ischemia.(4) The IGF- II positive neurons number in the cerebrum cortex of 2VO and 2VO+DS groups increased significantly in ischemia 8 weeks, then decreased gradually but not to normal level till ischemia 6month. But in all course of ischemia (within 6 months), the IGF- II positive neurons number in the cerebrum cortex of 2VO+DS group is always lower to the 2VO group at the same time point.(5) In 2VO group after ischemia 8 weeks, the ultrastructure changing in the cerebrum cortex neurons showed karyolysis, organelle dissolve decrease in cytoplast; At ischemia 16 weeks, the neuron structure have removed to integrated, but still have the ischemia exhibition such as karyotheca invagination, chromatin side aggregation, organelle dis-complete. Up to ischemia 24 weeks, the neurons have recovered to the normal structure. And in all course of ischemia (within 6 months), the cell structure of 2VO+DS group is always better to the 2VO group at the same time point.CONCLUSION:(1) The nNOS positive neurons number of Acb is reduce after ischemia but then come round to the normal level in the later, that demonstrated the function of NO in Acb isdifferent to the other brain section and may be restrained in earlier stage of ischmia.(2) The change of nNOS positive neurons number in S1 showed that the nNOS positive neurons increasing in earlier stage of ischmia is excitability increasing. And the reducing in the later is related to the neurons death in the ischemia middle and late stage.(3) The number of nNOS positive neurons in PVN increased significantly in the whole period of ischemia, which implied that the changes of nNOS activity in PVN might be related to the change... |
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