【摘要】 为探讨家兔房室结 3层细胞束细胞的电生理特性 ,按房室结 3层细胞束 4种细胞的形态特点 ,用胶原酶灌注分离房室结细胞并从中筛选 4种形态细胞 :圆形、椭圆形、细长形和条状形细胞 ,应用膜片钳全细胞记录技术观察各形房室结细胞超极化钳制电流的特征。超极化钳制时 ,房室结细胞中 12个条状形细胞中有 4个记录到较弱的内向整流钾电流 (Ik1 ) ,其他各形细胞均未记录到 Ik1 。大部分圆形和椭圆形细胞 (11 14 )记录到起搏电流 If,其电流密度为 - 4 .73± 0 .81p Ap F- 1 ,部分细长形细胞 (4 11)记录到较弱的 If,其电流密度为 - 0 .2 8± 0 .0 7p Ap F- 1 ,负向电流明显低于圆形和椭圆形细胞 (P<0 .0 1) ,长条形细胞除 1个外其余均未记录到 If。结果表明家兔房室结的 4种形态细胞的超极化钳制电流有明显不同 ,提示家兔房室结 3层细胞束的电生理及传导功能存在差异。更多还原

【Abstract】 The observation of phyperpolarization activated currents in four morphologically distinct cells (circular,ovoid,slender and thick cells) isolated from atrioventricular node (AVN) in 42 rabbits was used to discuss the electrophysiological properties and conductive function of three distinct layers in rabbit AVN by whole cell patch clamp technique.The results showed that the pacemaker current (I f) could be recorded in most circular and ovoid cells (11/14),some slender cells (4/11) and only one out of twelve thick cells during hyperpolarization.The current density of I f in circular and ovoid cells (-4.73±0.81 pApF -1 ) was higher than that in slender cells (-0.28±0.07 pApF -1 ) ( P <0.01).Faint inward rectifier currert (I k1 ) could be recorded in some thick cells (4/12),whereas could not be recorded in other AVN cells.The results suggest that distinct shaped cells isolated from different cellular bundles in rabbit AVN have different electrophysiological properties and conductive function.These mean that distinct cellular bundles have different conductive velocity.更多还原