鼠脑出血后部分脑区内皮素-1表达与脑水含量变化

The relationship between brain edema and expression of Endothelin-1 after intracerebral hemorrhage in rats

目的 探讨ET 1在脑出血继发性脑损伤中的作用。方法 通过脑内注射胶原酶建立大鼠脑出血模型 ,采用免疫组织化学技术观察脑出血后脑内ET 1表达与脑出血灶周围组织水肿之间的关系。结果 给大鼠尾壳核注射胶元酶 0 5IU ,4h后脑水含量即明显升高 ,2 4h达高峰 ,与此同时ET 1在皮层、海马等脑区的表达明显增多 ,并于2 4h达高峰。

Objective To characterize the alteration of expression of ET-1 in hippocampus and cerebral cortex after intracerebral hemorrhage (ICH) in order to determine whether progressive increase in edema and ischemic injury surrounding ICH is related to increased expression of ET-1.Methods In 60 adult female Sprague-Dawley rats,intracerebral hemorrhage was induced by injection of bacterial collagenase into the caudate nucleus.The animals were randomly divided into control and experimental groups.After 4,24,48,72 hours of ICH,morphological studies were performed by serial sections.By using immunohistochemical SP staining method and color image analysis,the expression of ET-1 in hippocampus and cerebral cortex was measured after ICH in rats.Brain edema was assayed by means of dry-wet weight method.Results ET-1-like immunoreactive neurons and astrocytes were markedly increased in extensive areas of hippocampus and cerebral cortex(P<0.05,P<0.01) and the increase was prominent in rats 24 hours after ICH as compared with control rats,accompanied by increase in brain water content (P<0.05,P<0.01).Color image analysis indicated a marked decrease in gray value of ET-1-positive cell bodies and a significant increase in ET-1-positive cell bodies in the CA1 and CA3 (P<0.05,P<0.01).Conclusions The results show that ET-1 may be one of the causes leading to perihematoma edema formation and ischemic injury.Therefore,ET-1 may play an important role in the pathogenesis of secondary brain injury after ICH.