通透Ca2+酸敏感离子通道1a的激活在糖尿病鼠局灶脑缺血损伤中的作用

摘要

Objective To observe the expression of acid-sensing ion channel la (ASICla) and to investigate the effect of intracellular Ca2 + concentration on focal cerebral ischemia in diabetic rats.Methods 108 male Wistar rats were divided into three groups:group A [rats with middle cerebral artery occlusion (MCAO)],group B [rats with MCAO and diabetes (DM + MCAO)],group C [rats with MCAO and diabetes treated with fasudil intervention (DM+ MCAO+ fasudil)] (n=36 each).Samples were obtained at the time points of 1,3,6 and 24 h after ischemia respectively (n=9).Models of MCAO and DM+MCAO were prepared.Rats in DM+MCAO+Fasudil group were treated with fasudil 1 mg/Kg by caudal vein injection after half an hour when DM+MCAO model successfully prepared.ASICla expressions were detected at different time points of ischemia in the 3 groups respectively.Ca2+ concentration in ischemia cortex cells were determined at different time points of ischemia in group B and C.Results ASICla expressions were gradually increased along with the ischemia time in group A and B (group A:0.71±0.10,0.80±0.11,0.86±0.08,0.93±0.09;groupB:0.86±0.11,1.05±0.51,2.42±0.08,2.78±0.04; all P＜ 0.05),and ASICla expressions at different time points were higher in group B than in group A (all P＜ 0.05).Ca2-concentration were gradually increased along with the ischemia time in group B (106.32± 18.6,137.84±14.32,151.94± 18.38,183.61±7.96,all P＜0.05).Compared with group B,the levels of ASICla expression and calcium current were reduced in group C.Conclusions The activation of ASICla increases calcium ion flow internal pathway leading to intracellular calcium overload,which may be one of the reasons for the aggravation of focal cerebral ischemia in diabetes.%目的 探讨酸敏感离子通道la(ASICla)的表达及细胞内Ca2+浓度的变化在糖尿病鼠局灶脑缺血损伤中的作用. 方法 取清洁级雄性Wistar大鼠108只,分为单纯脑缺血(MCAO)组、糖尿病脑缺血(DM+ MCAO)组和糖尿病脑缺血+法舒地尔干预(DM+ MCAO+ Fasudil)组,每组36只；各组分别在缺血1、3、6、24 h4个时间点留取标本,每个时间点9只.制备MCAO及DM+MCAO模型,DM+MCAO+Fasudil组在糖尿病造模成功后0.5h内尾静脉缓慢注射Fasudil 1 mg/Kg,分别检测三组不同缺血时间ASICla表达,同时检测DM+ MCAO组、DM+ MCAO+ Fasudil组两组不同缺血时间缺血周围皮层细胞内Ca2+浓度的变化. 结果 在1、3、6和24 h不同时间点对应的灰度值,MCAO组分别为0.71±0.10,0.80±0.11,0.86±0.08,0.93±0.09;DM+MCAO组分别为0.86±0.11,1.048±0.51,2.42±0.08,2.78±0.04;各时间点比较,差异均有统计学意义(均P＜0.05),DM+MCAO组高于MCAO组(t=4.673,P＜0.01)；DM+ MCAO细胞内钙离子浓度逐渐增加(106.32±18.63,137.84±14.32,151.94±18.38,183.61±7.96,P＜0.05),DM+MCAO+ Fasudil组ASICla与钙电流表达均降低. 结论 ASICla的激活所导致钙离子内流增加,细胞内钙超载可能是糖尿病局灶脑缺血损伤加重的原因之一.