内皮素在急性脊髓损伤中的变化

Changes of Endothelin in Acute Spinal Cord In jury

缺血是继发性脊髓损伤（ＳＣＩ）的重要机制之一，而内皮素（ＥＴ）是迄今所知作用最强、持续最久的缩血管多肽，并且ＥＴ也是一种能够在中枢神经系统中表达的神经递质。本实验通过观察ＳＣＩ后脊髓组织和血浆中ＥＴ含量的变化，研究ＥＴ与急性ＳＣＩ的关系，并探讨其可能的发生机制。方法：应用改良Ａｌｅｎ氏脊髓损伤模型，选用雄性ＳＤ大鼠４０只，造成５ｇ×１０ｃｍ强度的ＳＣＩ。应用放射免疫法（ＲＩＡ）测定ＳＣＩ后６小时、２４小时及１４天时脊髓组织和血浆中ＥＴ的浓度。分别在术前、ＳＣＩ后及处死前记录ＭＥＰ。结果：损伤后血浆中ＥＴ浓度无明显改变，而脊髓组织中的ＥＴ含量进行性升高。６小时上升至对照组的１１３％，２４小时上升至１２４％，１４天上升至１３９％。结论：ＳＣＩ后脊髓组织中ＥＴ含量迅速升高并且持续较长时间。

Ischemia is one of the most important mechanisms of secondary spinal cord injury (SCI).Endothelin (ET) is the most potent and long-lasting vasoconstrictive peptide,which is expressed in the central nervous system and may act as a neuromodulator.ET has been proved to play an important role in some cerebral vascular diseases,and there were also experimental evidence indicating the possible relationship between ET and SCI.In this study,the ET level in both spinal cord and plasma was measured after an acute experimenta lSCI in order to explain the relation between ET and acute SCI and to explore the possible origination of ET.The experimental acute SCI model was created by modified Allen’smethod. At 6h, 24h and 14d after SCI,ET level in spinal cord and plasma were measured by radioimmunoassay. After SCI, there was littlevariation of the concentrations of ET inplasma, while in the spinal cord the concentrations were elevated progressively during 14 days,from 113% at 6h to 139%in 14d.ET seems to play an important role in SCI as its level increased rapidly and lasted for long time after SCI.