Electrophysiological basis of arteriolar vasomotion in vivo
Electrophysiological basis of arteriolar vasomotion in vivo
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DOI：
10.1159/000054090
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发表时间：
2000-11-01
影响因子：
1.7
通讯作者：
Segal, SS
中科院分区：
文献类型：
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作者：
Bartlett, IS;Crane, GJ;Segal, SS
我们测试了这样的假设：膜电位（E-m）的周期性变化是麻醉仓鼠颊囊小动脉自发血管舒缩的基础，直径振荡（类似于3分钟（-1））先于平滑肌细胞（SMC）和内皮细胞（EC）的E-m振荡（类似于3秒）。 E-m振荡被分解为六个阶段：（1）在血管舒缩（-46 +/- 2 mV）期间观察到的最负E-m的周期（6 +/- 2 s）与在血管舒缩期间观察到的最大直径（41 +/- 2 m）的时间（8 +/- 2 s）相关（r = 0.87，p < 0.01）； (2) 缓慢去极化 (1.8 +/- 0.2 mV s(-1))，直径无变化； (3) 快速（9.1 +/- 0.8 mV s(-1)）去极化（至-28 +/- 2 mV）和收缩； (4)瞬时部分复极化(3-4mV)； (5) 血管舒缩期间最小直径 (27 +/- 2 m) 处持续 (5 +/- 1 s) 去极化 (-28 +/- 2 mV) 与时间 (3 +/- 1 s) 相关 (r = 0.78, p < 0.01); (6) 缓慢复极化 (2.5 +/- 0.2 mV s(-1)) 和松弛。 E-m 的绝对变化与最负的 E-m 相关（r = 0.60，p < 0.01）。硝普钠或硝苯地平引起持续的超极化和扩张，而四乙铵或升高的 PO2 引起持续的去极化和收缩。我们认为体内血管舒缩反映了 SMC 和 EC 的 E-m 的自发周期性变化，与跨质膜的阳离子通量相对应。版权所有 (C) 2000 S. Karger AG，巴塞尔。
We tested the hypothesis that cyclic changes in membrane potential (E-m) underlie spontaneous vasomotion in cheek pouch arterioles of anesthetized hamsters, Diameter oscillations (similar to3 min(-1)) were preceded (similar to3 s) by oscillations in E-m of smooth muscle cells (SMC) and endothelial cells (EC). Oscillations in E-m were resolved into six phases: (1) a period (6 +/- 2 s) at the most negative E-m observed during vasomotion (-46 +/- 2 mV) correlating (r = 0.87, p < 0.01) with time (8 +/- 2 s) at the largest diameter observed during vasomotion (41 +/- 2 m); (2) a slow depolarization (1.8 +/- 0.2 mV s(-1)) with no diameter change; (3) a fast (9.1 +/- 0.8 mV s(-1)) depolarization (to -28 +/- 2 mV) and constriction; (4) a transient partial repolarization (3-4 mV); (5) a sustained (5 +/- 1 s) depolarization (-28 +/- 2 mV) correlating (r = 0.78, p < 0.01) with time (3 +/- 1 s) at the smallest diameter (27 +/- 2 m) during vasomotion; (6) a slow repolarization (2.5 +/- 0.2 mV s(-1)) and relaxation. The absolute change in E-m correlated (r = 0.60, p < 0.01) with the most negative E-m. Sodium nitroprusside or nifedipine caused sustained hyperpolarization and dilation, whereas tetraethylammonium or elevated PO2 caused sustained depolarization and constriction. We suggest that vasomotion in vivo reflects spontaneous, cyclic changes in E-m of SMC and EC corresponding with cation fluxes across plasma membranes. Copyright (C) 2000 S. Karger AG, Basel.