CAJ | 학술논문

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10-7 mol/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＋50 mV和＋60 mV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＝＋50 mV，n＝10）和（27．49±2．71）pA/pF（Vm＝＋60 mV，n＝10），后者为（12．38±1．58）pA/pF（Vm＝＋50 mV，n＝6）和14．87±1．63 pA/pF（Vm＝＋60 mV，n＝6）。在内面向外式膜片下（Vm＝＋40 mV，[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＝（1912．8±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。
목적：탐토당뇨병환자장계막동맥혈관평활기세포（VSMCs）대전도개격활갑통도（BKCa ）적전류변화，천명당뇨병대장계막동맥적손상급기세포전생리궤제。방법장환자분위혈당정상적대조조（n＝19）화당뇨병조（n＝11），이용단통도막편겸급전세포천공막편겸기술기록량조환자장계막동맥 VSMCs BKCa전류적변화，병비교증가욕액중개리자농도[（Ca2＋）i]지10-7 mol/L시량조BKCa단통도전류적변화。결과재전세포천공막편겸하，측시전압범위내，막전위분별위＋50 mV화＋60 mV시，대조조적전류밀도명현고우당뇨병조（P＜0．05），전자위（20．85±2．66）pA/pF（Vm＝＋50 mV，n＝10）화（27．49±2．71）pA/pF（Vm＝＋60 mV，n＝10），후자위（12．38±1．58）pA/pF（Vm＝＋50 mV，n＝6）화14．87±1．63 pA/pF（Vm＝＋60 mV，n＝6）。재내면향외식막편하（Vm＝＋40 mV，[Ca2＋]free＝0），대조조 BKCa단통도활성명현강우당뇨병조（P＜0．05），대조조 Tc＝（622．6±173．8）ms，NPo＝0．021±0．006（n＝8），당뇨병조 Tc＝（1912．8±346．6）ms，NPo＝0．005±0．001（n＝8）。증가욕액중[Ca2＋]i지10-7 mol/L시，대조조BKCa통도활성명현증강（P＜0．05），Tc＝（194．1±40．1）ms，NPo＝0．058±0．014（n＝7）。단당뇨병조BKCa단통도전류폭도，통도개방시간，관폐시간화통도평균개방개솔균무명현변화。결론당뇨병환자인 VSMCs BKCa단통도개방개솔감소화전류밀도강저，차대Ca2＋반응성강저，저가능시당뇨병장계막동맥공능손상적원인。
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±2.66)pA/pF(Vm=+ 50 mV,n=10)and(27.49± 2.71)pA/pF(Vm=+ 60 mV,n=10)and the latter was(12.38±1.58)pA/pF(Vm=+ 50 mV,P<0.05,n=6)and(14.87± 1.63)pA/pF(Vm=+ 60 mV,P<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±173.8)ms,NPo=0.021 ± 0.006(n=8)in the normal blood glucose group and Tc=(1 912.8±346.6)ms(P<0.05,n=8),NPo=0.005±0.001 (P<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±40.1)ms(P<0.05,n=7),NPo=0.058 ±0.014(P<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 of BKCa single channel opening probability,the decrease of current density of BKCa and the lower response to calcium ions in human VSMCs may be a potential cause for mesenteric arterial function inj ury in diabetes mellitus.