前脑缺血及再灌流损伤后大脑皮层内皮素、降钙素基因相关肽和神经元凋亡的研究

Study of ET, CGRP and Neuron Apoptosis after Forebrain Ischemia and Reperfusion Injury

目的:探讨大脑皮层缺血及再灌流内皮紊(ET)、降钙素基因相关肽(CGRP)与神经元凋亡的变化规律及关系。方法:以前脑缺血及再灌流不同时段的大鼠为模型,用放免法检测皮层ET和CGRP含量;TUNEL法检测原位细胞凋亡。结果:缺血后15分,ET低于正常和假手术组;再灌流后进一步降低,12小时达最低水平,6天后恢复。缺血后CGRP升高,再灌流后继续升高,12小时和1天达高峰后下降,6天时恢复正常。缺血后神经元凋亡增加,再灌流后继续增加,1天时达高峰后缓慢下降,8天时基本恢复正常。ET量与凋亡细胞呈负相关。CGRP量与凋亡细胞呈正相关。结论:缺血和再灌流均可导致神经元凋亡。CGRP在缺血及再灌流早期升高,其对神经元凋亡可能具有双重作用。

Objective: To study endothelin (ET), calcitonin gene-related peptide (CGRP) and neuron apoptosis after forebrain ischemia and reperfusion injury. Methods: The contents of ET and CGRP were qualified with a radioimmunoassay method and the neuron apoptosis was detected with TUNEL method in rats with ischemic forebrain and reperfusion at different time courses. Results: After 15-minute ischemia, the level of ET in experimental group was lower than that in normal or pseudooperative group (P<0.05). Their contents further reduced after reperfusion, reached the lowest level at 12-hour reperfusion (P<0.05) and became normal six days later. After 15-minute ischemia, the level of CGRP in experimental group was higher than that in normal or pseudooperative group (P<0.05). It continue rise, reached the top at 12-hour or the first day (P<0.05) and became normal six days later. The number of neuron apoptosis increased after ischemia and continued to increase after reperfusion. After reaching the top at the first day of reperfusion, it decreased gradually and became normal eight days later. There were a negative relationship between ET and apoptosis and a positive relationship between CGRP and apoptosis. Cvonclusion: Both ischemia and reperfusion could induce neuron apoptosis. The level of CGRP increases both in ischemia and early reperfusion, which might have double effect on neuron apoptosis.