中文摘要：

本研究应用电生理技术在豚鼠离体小脑前下动脉（anterior inferior cerebellar artery,AICA）、肠系膜动脉（mesenteric artery,MA）和耳蜗螺旋动脉（spiral modiolar artery,SMA）分支（直径小于100μm）上比较微动脉平滑肌细胞电生理学特性的异同。结果显示：（1）应用细胞内微电极记录技术测得AICA、MA和SMA细胞静息膜电位分别为（-68±1.8）（n=65）、（-71±2.4）（n=80）和（-66±2.9）mV（n=58）,各微动脉间无统计学差异。（2）一段血管微动脉标本全细胞膜片钳记录的平滑肌细胞膜电容和膜电导都远大于单个细胞标本,且微动脉间存在统计学差异,大小顺序为MA〉AICA〉SMA。应用缝隙连接阻断剂2-APB（100μmol/L）后记录一段微动脉平滑肌细胞膜电容和膜电导与单个细胞十分接近。（3）AICA、MA和SMA单个平滑肌细胞膜电流I/V关系呈明显的外向整流特性,都对1mmol/L4-AP和10mmol/LTEA敏感。当指令电压为＋40mV时,AICA、MA和SMA血管平滑肌细胞电流密度分别为（26±2.0）、（24±1.7）和（18±1.3）pA/pF,SMA和AICA、MA间存在统计学差异。上述结果提示,豚鼠不同部位微动脉平滑肌细胞在缝隙连接耦联力和电流密度等电生理特性存在差异。

英文摘要：

Arterioles are major contributors to the control of systemic blood pressure and local blood flow.In this study,we compared electrophysiological properties of vascular smooth muscle cells（VSMCs） in anterior inferior cerebellar artery（AICA）,mesenteric artery（MA） and spiral modiolar artery（SMA） by intracellular microelectrode recording and whole-cell patch clamp recording techniques.Results were shown as below：（1） Intracellular microelectrode recordings were made from VSMCs in AICA,MA and SMA with resting potentials of（-68±1.8）（n=65）,（-71±2.4）（n=80） and（-66±2.9） mV（n=58）,respectively.There was no significant difference in resting potentials among arterioles.（2） The membrane capacitance and membrane conductance in situ cells were much larger than those in dispersed smooth muscle cells by whole-cell recording techniques,and there was significant difference among arterioles,which were in the order：MAAICASMA.After application of gap junction blocker 2-APB（100μmol/L）,the membrane capacitance and membrane conductance in situ cells were very close with those in single smooth muscle cells.（3） The I/V relation of whole-cell current of dissociated smooth muscle cells（AICA,MA and SMA） showed a prominent outward rectification,and the currents were substantially inhibited by 1 mmol/L 4-AP or 10 mmol/L TEA.When the command voltage was ＋40 mV,the current densities of VSMCs in AICA,MA and SMA were（26±2.0）,（24±1.7） and（18±1.3） pA/pF respectively.SMA showed significant difference in the current density from AICA and MA respectively.These results suggest that the electrophysiological properties of coupling strength of gap junction and current density of smooth muscle cells are different among arterioles in the guinea pig.