环孢素抑制未成熟脑惊厥性脑损伤大鼠多药耐药基因的剂量探讨

Investigation of Dosage of Ciclosporin to Inhibit Multidrug Resistance Gene in Immature Rats with Convulsion Brain Damage

目的探讨环孢素对未成熟脑惊厥性脑损伤大鼠多药耐药基因表达的抑制作用及其剂量依赖性和不良反应。方法 21日龄雄性SD大鼠67只分为5组:假手术组(A组)、模型对照组(B组)、环孢素10mg.kg-1干预组(C组)、环孢素5mg.kg-1干预组(D组)、环孢素25mg.kg-1干预组(E组),22日龄时制作氯化锂-匹鲁卡品癫模型(A组除外),采用环孢素每次10mg.kg-1、5mg.kg-1、25mg.kg-1分别在造模后6h、30h、54h腹腔注射干预,观察大鼠造模72h病死率、行为变化、体质量变化、脑海马CA1区电镜神经元形态变化及多药耐药基因产物P-糖蛋白(P-gp)表达水平。结果 1.总体病死率为26.9%,B组病死率为16.7%,采用环孢素干预,最小剂量5mg.kg-1.次-1干预可显著降低病死率,达到A组水平,而中间剂量10mg.kg-1.次-1干预也可显著降低病死率至9.1%,但25mg.kg-1.次-1干预可提高病死率至38.5%。2.B组行为能力差,E组行为能力最差,而D组行为能力与A组接近。3.各组间体质量变化无明显差异。4.环孢素干预可以减轻惊厥幼鼠脑海马CA1区神经细胞水肿程度,减轻凋亡核固缩程度,减轻线粒体水肿,保护细胞间连接,但C、D、E组间差别不明显。5.B组脑海马CA1区多药耐药基因表达产物P-gp的灰度值及阳性细胞数分别为110.44±16.70及(1444.44±271.85)mm-2,环孢素干预可以使其表达显著降低,D组与C组效果比较差异无统计学意义,E组也有降低作用,虽有统计学意义,但不及C、D组作用明显。结论环孢素可以通过降低惊厥幼年雄性SD大鼠脑P-gp表达水平对未成熟的惊厥性脑损伤后多药耐药基因表达进行抑制,环孢素中小剂量应用效果明显,5mg.kg-1.次-1连用3次效果最佳,且不良反应不明显。

Objective To investigate the inhibition effects and the dose of ciclosporin to inhibit multidrug resistance gene in nonage brain with convulsion brain damages and their untoward reactions.Methods Sixty-seven 21 days male SD rats had been investigated,which were divided into 5 groups：pseudomodel group（group A）,model control group（group B）,ciclosporin 10 mg.kg-1 intervention group（group C）,ciclosporin 5 mg.kg-1 intervention group（group D）,ciclosporin 25 mg.kg-1 intervention group（group E）,which were given Licl pilucarpin to get the epileptic models（group A had been excepted）,ciclosporin was used 3 times for 6 hours,30 hours,54 hours,respectively,in 3 different doses（5 mg.kg-1,10 mg.kg-1,25 mg.kg-1 each time）,and their mortality rate,behavior,weight,electron microscope findings,and the expression levels of P-gp in CA1 area of hippocampus were observed at 72 hours after the models were established.Results 1.The gross mortality rate was 26.9%,the mortality rate in group B was 16.7%,ciclosporin intervention as 5 mg.kg-1 each time could decrease the mortality rate,as to the group A,and the middose of 10 mg.kg-1 each time ciclosporin intervention could decrease the mortality rate to 9.1%,but the high dose 25 mg.kg-1 every time could increase the mortality rate to 38.5%.2.The behaviors in group B were bad,group E worse,group D the best,compared to the behaviors of group A.3.There was no significant difference in rat weight among 5 groups.4.Ciclosporin intervention could reduce the edema level of neurocells and the cell chondriosomes,reduce apoptotic nucleus granuling,and protect the intercellular link,but there was no significant difference among 3 groups in different doses.5.The gray scale of P-gp and the number of P-gp positive cell in CA1 area of hippocampus in group B were 110.44±16.70 and（1 444.44±271.85） mm-2,the intervention of ciclosporin could decrease the expression levels,there was no significant difference between group D and group C,their was significant deduce effect in group E also,but it was less than that in the other 2 groups.Conclusions Ciclosporin can reduce the level of P-gp in male SD nonage brain with convulsion brain damages,so it can inhibit multidrug resistance genes in nonage brain with convulsion brain damages,the middle and small dose of ciclosporin intervention can have significant effects,5 mg.kg-1 every time for 3 times has the best effects without untoward reactions.