脑复合剂对脑损伤大鼠Na+-K+-ATP酶、Ca2+-ATP酶活性及Ca2+调控的影响

目的 观察刨伤性脑损伤(traumatic brain injury,TBI)大鼠脑组织匀浆及线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性、神经细胞内游离Ca2+浓度及脑组织钙调蛋白(CaM)表达的动态变化,探讨脑复合剂脑保护作用的分子生物学机制.方法 建立大鼠TBI模型,分别设立假手术组、TBI组及中药治疗组.中药治疗组给予脑复合剂10 g·kg-1·d-1,假手术组及TBI组给予同等剂量等渗盐水,2次/d,连续7 d.分别于TBI后24 h、72 h、1周等3个时相点处死大鼠,动态定量分析各组大鼠脑组织匀浆及线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性、神经细胞内游离Ca2+浓度及脑组织CaM表达的变化.结果 TBI组各时相点大鼠脑组织匀浆及线粒体Na+-K+-ATP酶、Ca2+-ATP酶活性均明显降低,于TBI后72 h后逐渐恢复,1周时仍明显低于假手术组.中药治疗组大鼠脑组织Na+-K+-ATP酶、Ca2+-ATP酶活性显著增加(P＜0.05);TBI组各时相大鼠脑组织神经细胞内游离Ca2+浓度及脑组织CaM表达均有不同程度增高,于伤后24 h达高峰,持续至72 h仍高于假手术组.而中药治疗组各时相大鼠神经细胞内游离Ca2+浓度及脑组织CaM表达明显低于TBI组(P＜0.05).结论 脑复合剂的脑保护作用可能与增加脑组织Na+-K+-ATP酶、Ca2+-ATP酶的活性,从而减轻TBI后脑细胞的能量代谢障碍,降低神经细胞内游离Ca2+浓度及脑组织CaM表达,减轻Ca2+超载所导致的继发性脑损伤有关.

Effect of compound decotion on activities of Na+-K+-ATPase and Ca2+-ATPase and regulation of Ca2+ after traumatic brain injury

Objective To dynamically observe the effect of compound decotion on changes of Na+-K+-ATPase,Ca2+-ATPase activity,intracellular free Ca2+ contents and CaM expression jn bomogenate and mitochondria of rat brain tissues after traumatic brain injury(TBI)and investigate the molecular mechanism of neuroprotective effect of compound decotion.Methods Rat TBI models were made and divided into sham operation group,TBI group and compound decotion treatment group(treated with comof normal saline,twice per day for seven days.Rats were sacrificed at 24 h,72 h and 1 week after injury to dynamically observe activities of Na+-K+-ATPase and Ca2+-ATPase in bomogenate and mitochondria of rat brain tissues,concentration of free Ca2+ in neurocytes and expression change of CaM in brain tissues.Results The activities of Na+-K+-ATP ageand Ca2+-ATPase in homogenates and mitochondria of brain tissues markedly decreased at different time point and increased gradually after 72 hours in TBI group but wag still lower than that of sham operation group at one week after injury.However,compound decotion could significantly enhance the activities of Na+-K+-ATPageand Ca2+-ATPage(P＜0.05).In TBI group,concentration of free Ca2+ in neurocytes and CaM expression in brain tissues were elevated at different degrees at different time point and reached peak at 24 hours after injury but still lower than that of sham operation group at 72 hours.While concentration of free Ca2+ in neurocytes and CaM expression in brain tissues were significantly lower than those of TBI group at different time point(P＜0.05).Conclusions The neuroprotective effect of compound decotion may be related to its role in increasing activities of Na+-K+-ATPase and Ca2+-ATPase to facilitate cellular metabolism and decreasing concentration of free Ca2+ in neurocytes and CaM expression in brain tissues to mitigate secondary brain injury induced by Ca2+ over load.