自发性蛛网膜下腔出血对鼠脑皮质和穿支动脉平滑肌细胞电压依赖性钾通道电流的差异性抑制作用  

The different suppression on voltage-dependent potassium channels currents of smooth muscle cells from cerebral pial arteries and penetrating arteries by subarachnoid hemorrhage

作　　者：王飞[1] 王焕之[1] 李世鹏[1] 孙涛[1] 马以骝[1] 余化霖[1] 

机构地区：[1]昆明医科大学第一附属医院神经外二科,650032

出　　处：《中华神经科杂志》2014年第12期871-875,共5页Chinese Journal of Neurology

基　　金：国家自然科学基金资助项目（81260182）;云南省科技厅联合专项研究基金资助项目（2012FB036）

摘　　要：目的 探讨自发性蛛网膜下腔出血（SAH）是否对脑皮质动脉和穿支动脉电压依赖性钾通道（Kv）电流的抑制作用存在差异.方法 制备大鼠SAH模型,72 h后用酶促消化法急性分离脑皮质动脉和穿支动脉的平滑肌细胞,运用膜片钳技术分别研究其静息电位和Kv电流.结果 SAH使皮质动脉[（45.63±1.18） mV]和穿支动脉[（41.55±1.19） mV]静息电位均减小且后者更为显著（F=8.24,P＜0.05; F=9.36,P＜0.01）;1μmol/L 4-氨基吡啶（4AP）可使正常皮质动脉[（38.76±1.03） mV]、正常穿支动脉[（38.53±0.67） mV]、SAH皮质动脉[（36.87±1.49） mV]和SAH穿支动脉[（37.89±1.24）mV]平滑肌细胞静息电位下降至同一水平（F=3.08,P＞0.05）.SAH使皮质动脉和穿支动脉脑动脉平滑肌细胞最大电流密度减小且后者更为显著（20.82±0.59与15.15±0.37,F=6.22,P＜0.05）,1μmol/L 4AP均可使正常皮质动脉（9.15±0.16）、正常穿支动脉（9.04±0.36）、SAH皮质动脉（8.77±0.26）和SAH穿支动脉（9.12 ±0.17）的Kv电流最大密度下降至同一水平（F=2.96,P＞0.05）.结论 SAH和Kv阻滞剂对Kv电流抑制作用的机制较接近,并且SAH对穿支动脉平滑肌细胞静息电位和Kv电流最大密度的抑制作用大于皮质动脉,推测该差异性可能与皮质动脉和穿支动脉对CVS的敏感性不同有关.Objective To study the effect of subarachnoid hemorrhage （SAH） on voltagedependent potassium channels （Kv） currents of smooth muscle cells,which is hypothesized to be different between cerebral pial arteries and penetrating arteries.Methods Smooth muscle cells from cerebral pial arteries and penetrating arteries in rats were enzymatically isolated 72 h after SAH,and patch clamp was used to test the relative cell size,resting potential and Kv currents.Results Resting potential of either pial （（45.63 ±1.18） mV） or penetrating artery （（41.55-± 1.19） mV） was shifted positively by SAH,even more significantly in latter （F =8.24,P ＜ 0.05 ; F =9.36,P ＜ 0.01） ; Resting potential of pial artery of control （（38.76 ± 1.03） mV）,penetrating artery of control （（38.53 ± 0.67） mV）,pial artery of SAH （（36.87 ± 1.49） mV） and penetrating artery of SAH（（37.89 ± 1.24） mV） were shifted positively to the same level by 1 μmol/L 4-aminopyridine （4AP; F =3.08,P ＞0.05）.Maximum Current Density （Imax） of either pial （（20.82 ±0.59） pA/pF） or penetrating artery （（15.15 ±0.37） pA/pF） was compromised by SAH,also more significantly in latter （F =6.22,P ＜ 0.05） ; Imax of pial artery of control （9.15 ± 0.16）,penetrating artery of control （9.04 ± 0.36）,pial artery of SAH （8.77 ± 0.26） and penetrating artery of SAH （9.12 ± 0.17） were decreased to the same level by 1 μmol/L 4AP （F =2.96,P ＞ 0.05）.Conclusions SAH probably shares the similar pathway with Kv blocker （4AP） in Kv currents inhibition.Further,SAH differently inhibits smooth muscle cells Kv currents and resting potential of cerebral pial arteries and penetrating arteries,which may be related with their different sensitivity towards cerebral vasospasm following SAH.

关 键 词：蛛网膜下腔出血 脑动脉 肌 平滑 血管 钾通道 膜片钳术 

分 类 号：R743.3[医药卫生—神经病学与精神病学]