糖尿病患者肠系膜动脉平滑肌细胞大电导钙激活钾通道电流的变化  

Changes of large-conductance calcium-activated potassium channels of mesenteric artery smooth muscle cells in diabetic patient

作　　者：文静[1,2] 程俊[1,2] 李鹏云[1,2] 李畅[1,2] 杨艳[1,2] 

机构地区：[1]泸州医学院心肌电生理学研究室 [2]泸州医学院心肌电生理学省部共建教育部重点实验室,四川泸州646000

出　　处：《重庆医学》2014年第18期2312-2315,共4页Chongqing medicine

摘　　要：目的探讨糖尿病患者肠系膜动脉血管平滑肌细胞(VSMCs)大电导钙激活钾通道(BKCa)的电流变化,阐明糖尿病对肠系膜动脉的损伤及其细胞电生理机制。方法将患者分为血糖正常的对照组(n=19)和糖尿病组(n=11),利用单通道膜片钳及全细胞穿孔膜片钳技术记录两组患者肠系膜动脉VSMCs BKCa电流的变化,并比较增加浴液中钙离子浓度[(Ca2+)i]至10-7mol/L时两组BKCa单通道电流的变化。结果在全细胞穿孔膜片钳下,测试电压范围内,膜电位分别为+50mV和+60mV时,对照组的电流密度明显高于糖尿病组(P<0.05),前者为(20.85±2.66)pA/pF(Vm=+50mV,n=10)和(27.49±2.71)pA/pF(Vm=+60mV,n=10),后者为(12.38±1.58)pA/pF(Vm=+50mV,n=6)和14.87±1.63pA/pF(Vm=+60mV,n=6)。在内面向外式膜片下(Vm=+40mV,[Ca2+]free=0),对照组BKCa单通道活性明显强于糖尿病组(P<0.05),对照组Tc=(622.6±173.8)ms,NPo=0.021±0.006(n=8),糖尿病组Tc=(1 912.8±346.6)ms,NPo=0.005±0.001(n=8)。增加浴液中[Ca2+]i至10-7 mol/L时,对照组BKCa通道活性明显增强(P<0.05),Tc=(194.1±40.1)ms,NPo=0.058±0.014(n=7)。但糖尿病组BKCa单通道电流幅度,通道开放时间,关闭时间和通道平均开放概率均无明显变化。结论糖尿病患者人VSMCs BKCa单通道开放概率减少和电流密度降低,且对Ca2+反应性降低,这可能是糖尿病肠系膜动脉功能损伤的原因。Objective To investigate the changes of large-conductance calcium-activated potassium channels（BKCa ）of mesenteric artery smooth muscle cells（VSMCs）in the patient with diabetes mellitus and to elucidate the mesenteric arterial inj ury caused by diabetes mellitus and its cellular electrophysiology mechanism.Methods Patients were divided into two groups：the diabetes melli-tus group and the normal blood glucose control group.The changes of BKCa electricity of VSMCs in the two groups were recorded by using the single channel patch clamp and the perforated whole-cell patch clamp techniques and the changes of BKCa single channel electricity at 10-7 mol/L free Ca2＋i in the bath fluid were compared between the two groups.Results In the perforated whole-cell patch-clamp,the current density of BKCa at the membrane potential of ＋50 mV and ＋60 mV in the normal blood glucose group was higher than that in the diabetes mellitus group,the former was（20.85＆#177;2.66）pA/pF（Vm=＋ 50 mV,n=10）and（27.49＆#177; 2.71）pA/pF（Vm=＋ 60 mV,n=10）and the latter was（12.38＆#177;1.58）pA/pF（Vm=＋ 50 mV,P＆lt;0.05,n=6）and（14.87＆#177; 1.63）pA/pF（Vm=＋ 60 mV,P＆lt;0.05,n=6）.In inside-out patch（Vm=＋ 40 mV,[Ca2＋]free=0）,the BKCa single channel activity in the normal blood glucose group was significantly stronger than that in the diabetes mellitus group,Tc=（622.6＆#177;173.8）ms,NPo=0.021 ＆#177; 0.006（n=8）in the normal blood glucose group and Tc=（1 912.8＆#177;346.6）ms（P＆lt;0.05,n=8）,NPo=0.005＆#177;0.001 （P＆lt;0.05,n=8）in the diabetes mellitus group.At 10-7mol/L free Ca2＋,the BKCa channel activity in the normal blood glucose group was increased significantly,Tc=（194.1＆#177;40.1）ms（P＆lt;0.05,n=7）,NPo=0.058 ＆#177;0.014（P＆lt;0.05,n=7）,but the ampli-tude of BKCa single channel current,channel opening time,turn-off time and the average channel opening probability in the diabetes mellitus group had no obvious changes.Conclusion The decrease

关 键 词：糖尿病 大电导钙激活钾通道 肠系膜动脉 

分 类 号：R587.1[医药卫生—内分泌]