大鼠局灶性脑损伤后calpain1和calpain2的表达

目的探讨大鼠局灶性脑损伤后钙激活中性蛋白酶1和2（calpain1,calpain2）表达规律与损伤时间的相关性。方法健康成年雄性SD大鼠50只,体重200～250g。随机分为10组,每组5只,其中实验组8组,对照组和假手术组各1组。应用免疫组化染色法,检测大鼠脑损伤后不同时程损伤周边区calpain1和calpain2的表达变化。结果对照组及假手术组均有capain1和calpain2表达。伤后15min,损伤周边区calpain1/calpain2阳性染色开始增强,伤后12h达高峰,24h逐渐减弱,5d阳性表达增强达另一高峰,随后逐渐减弱,至15d接近对照组水平。除伤后15d组外,其余实验组与对照组比较,calpain1和calpain2阳性反应物面积百分比及平均光密度值差异均具有统计学意义（P〈0.05）。结论在正常大鼠脑组织中calpain1和calpain2均有表达,局灶性脑损伤后,损伤周边区calpain1和calpain2的表达随时间呈较典型的双峰变化。

Dynamic changes of calpain1 and calpain2 after traumatic brain injury in rats

Objective To illuminate the relationship between the expression of calpain1 and calpain2 and the time course of traumatic brain injury.Methods 50 adult male Sprague-Dawley rats weighting 200～250g were divided into ten groups randomly(5 rats each group).Rats were decapitated at 15min,12,24 hours,3,5,7,10and 15 days after brain injury.The changes of calpain1 and calpain2 expression were assessed by immunohistochemistry.The results were analyzed using the Motic Images Advanced 3.2 software.Results The positive staining cells were observed both in control and sham group adjacent to injury.The calpain1 and calpain2 positive staining was remarkably increased and reached the maximal level at 12h after focal brain injury,decreased after 24h,markedly increased again at day 5,and then gradually decreased from day 7 to 15.Compared with control group,the injury groups have significantly increase on the area percentage and average optical density of calpain1 and calpain2 positive cells.Conclusion Both calpain1 and calpain2 could be detected in normal rat brain.The expressions of calpain1 and calpain2 protein show a typical double-peak change and may have a possible relationship with the extended periods of time after brain injury.