Expression Of TNF-α MRNA In Neurons And Astrocytes After Middle Cerebral Artery Occlusion In Hypertensive Rats

Objective: To examine the cellular localization of TNF- a mRNA after focal cerebral ischemia in hypertensive rats, and investigate the relationship between TNF- a levels and cerebral damage. To observe the infarction volume after middle cerebral artery occlusion(MCAO)in hypertensive rats and observe the patholog change. Methods: First the renovascular hypertensive rats were made by two-kidney-two-clip(2K2C). The hypertensive rats were randomly divided into ten groups: sham-operated control group, ischemia 1-hour(lh) group, ischemia 2h group, ischemia 2h and reperfused 3h, 6h, 12h, 24h, 3day(3d), 5d, 7d groups. MCAO was achieved by Koizumi method. Level and celllar sources of TNF- a mRNA were examined by combined in situ hybridization and immunocytochemistry. The infarction volume was observed by 2,3,5-triphenyltetrazolium(TTC) stain. Results: (1) The success rate and stabilization of MCAO models in 2K2C hypertensive rats. (2) The positive cell of TNF-a mRNA increased in ischemia 1-hour group, and to be highest in ischemia 2h reperfused 12h group. (3) Double staining showed that the main cells containing TNF- a mRNA were neurons in early time, then were astrocytes and neurons. Many other cells express TNF- a mRNA in the post time of ischemia-reperfusedinjury. TNF-α mRNA Conclusion: (1) MCAO models in 2K2C hypertensive rats can similarly imitate the pathophysiological state of cerebral infarction in hypertensive patients. (2) Astrocytes and neurons express TNF-α mRNA in ischemia-reperfused injury .