RABBIT SINOATRIAL NODE CELLS - ISOLATION AND ELECTROPHYSIOLOGICAL PROPERTIES
RABBIT SINOATRIAL NODE CELLS - ISOLATION AND ELECTROPHYSIOLOGICAL PROPERTIES
复制标题
DOI：
10.1113/jphysiol.1990.sp018219
复制
发表时间：
1990-09-01
影响因子：
5.5
通讯作者：
BROWN, HF
中科院分区：
文献类型：
--
作者：
DENYER, JC;BROWN, HF
1.本研究建立了一种分离耐钙的单个兔窦房结细胞的方法，该方法分离后能保持其自然形状。大多数活的自发活性细胞被拉长，测得长度约为100 μ m。2.用苏木精-伊红染色固定的细胞显示，具有突起的“细胞”通常是一个以上细胞的聚集体。3.单一的，细长的，自发活动的细胞电流和电压钳使用全细胞配置的膜片钳记录技术。记录的自发活动和时间依赖性电流与之前在多细胞结制备物和单细胞中报道的相似。4.对L-型钙电流下降的时间过程进行评估：通常观察到10 - 20分钟的稳定期，然后是快速下降（约2分钟）。5.在大多数细胞中，一个快速的，TTX敏感的Na+电流成分。少数细胞显示瞬时外向K+电流（iA）。6.超极化激活电流的激活范围因细胞而异。在大多数搏动活跃的细胞中，if的阈值接近最大舒张电位（在大多数细胞中约为-65 mV），但在其他细胞中，在起搏器范围内无法记录if。7. MnCl 2的毫摩尔浓度引起了显着增加，如果，但只有当移液管溶液不包含EGTA。EGTA（缓冲Ca 2+至pCa 8）的加入显著降低了Mn 2+的作用，因此可能是通过抑制Na+-Ca 2+交换和随后的细胞内Ca 2+浓度升高而发生的。
1. A method has been developed for isolating calcium-tolerant, single rabbit sinoatrial node cells which maintain their natural shape following isolation. The majority of viable, spontaneously active cells were elongated and measured about 100 .mu.m in length. 2. Staining fixed cells with Haematoxylin-Eosin revealed that a ''cell'' with projections was usually an aggregate of more than one cell. 3. Single, elongated, spontaneously active cells were current and voltage clamped using the whole-cell configuration of the patch-clamp recording technique. The spontaneous activity and time-dependent currents recorded were similar to those reported previously in multicellular nodal preparations and in single cells. 4. An assessment was made of the time course of L-type calcium current rundown: a stable period of between 10 and 20 min followed by a rapid run-down (over about 2 min) was typically observed. 5. In most cells, a fast, TTX-sensitive Na+ current component was seen. A few cells showed a transient outward K+ current (iA). 6. The activation range for the hyperpolarization-activated current, if, varied from cell to cell. In the majority of actively beating cells, the threshold for if was near the maximum diastolic potential (about -65 mV in most cells) but in other cells, no if could be recorded within the pacemaker range. 7. Millimolar concentrations of MnCl2 caused a marked increase in if, but only when the pipette solution did not contain EGTA. Inclusion of EGTA (to buffer Ca2+ to about pCa 8) significantly reduced the effect of Mn2+ which therefore probably occurs through inhibition of Na+-Ca2+ exchange and consequent rise in intracellular Ca2+ concentration.