Role of calcium stores and membrane voltage in the generation of slow wave action potentials in guinea‐pig gastric pylorus
Role of calcium stores and membrane voltage in the generation of slow wave action potentials in guinea‐pig gastric pylorus
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钙储存和膜电压在豚鼠胃幽门慢波动作电位产生中的作用
DOI：
--
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
P. Dosen
中科院分区：
文献类型：
--
作者：
D. Helden;M. Imtiaz;K. Nurgaliyeva;P. V. D. Weid;P. Dosen
1 在内脏平滑肌单束条中进行的细胞内记录显示有节奏的自发膜去极化，称为慢波 (SW)。这些表现出“起搏器”和“再生”成分，由称为自发短暂去极化（STD）的更基本事件的总和组成。 2 STD 和 SW 在河豚毒素、硝苯地平和兰尼定存在下以及短暂接触不含 Ca2+ 的含 Cd2+ 溶液后持续存在；它们被 ACh 增强，并被 BAPTA AM、环吡嗪酸和咖啡因阻断。 SWs 在肝素负载试纸条中也受到抑制。在较宽的膜电位范围（例如 ‐80 至 ‐45 mV）内观察到 3 个 SW，且去极化电位越高，频率越高。 4 解剖过程后，用生理盐水向组织灌注 1-3 小时，此制剂中开始有规律的自发 SW 活动。在这种活动开始之前施加的膜去极化会引发类似 STD 的事件的爆发（称为“初始”反应），当大于阈值水平时，会引发再生反应。组合的初始再生波形被称为类 SW 动作电位。 5 电压引起的反应表现出较大的可变潜伏期（典型范围为 0.3-4 秒）、约 11 秒的不应期以及与 STD 和自发性 SW 无法区分的药理学。 6 数据表明，SWs 通过更基本的肌醇 1,4,5-三磷酸 (IP3) 受体诱导的 Ca2+ 释放事件产生，这些事件有节奏地同步触发再生 Ca2+ 释放并诱导穿过质膜的内向电流。动作电位（与 SW 没有区别）可以通过去极化引起，这一发现表明膜电位调节 IP3 的产生。细胞内 IP3 敏感 Ca2+ 释放的电压反馈可能对 SW 的产生和传播产生重大影响。
1 Intracellular recordings made in single bundle strips of a visceral smooth muscle revealed rhythmic spontaneous membrane depolarizations termed slow waves (SWs). These exhibited ‘pacemaker’ and ‘regenerative’ components composed of summations of more elementary events termed spontaneous transient depolarizations (STDs). 2 STDs and SWs persisted in the presence of tetrodotoxin, nifedipine and ryanodine, and upon brief exposure to Ca2+‐free Cd2+‐containing solutions; they were enhanced by ACh and blocked by BAPTA AM, cyclopiazonic acid and caffeine. SWs were also inhibited in heparin‐loaded strips. 3 SWs were observed over a wide range of membrane potentials (e.g. ‐80 to ‐45 mV) with increased frequencies at more depolarized potentials. 4 Regular spontaneous SW activity in this preparation began after 1–3 h superfusion of the tissue with physiological saline following the dissection procedure. Membrane depolarization applied before the onset of this activity induced bursts of STD‐like events (termed the ‘initial’ response) which, when larger than threshold levels initiated regenerative responses. The combined initial‐regenerative waveform was termed the SW‐like action potential. 5 Voltage‐induced responses exhibited large variable latencies (typical range 0.3‐4 s), refractory periods of ≈11 s and a pharmacology that was indistinguishable from those of STDs and spontaneous SWs. 6 The data indicate that SWs arise through more elementary inositol 1,4,5‐trisphosphate (IP3) receptor‐induced Ca2+ release events which rhythmically synchronize to trigger regenerative Ca2+ release and induce inward current across the plasmalemma. The finding that action potentials, which were indistinguishable from SWs, could be evoked by depolarization suggests that membrane potential modulates IP3 production. Voltage feedback on intracellular IP3‐sensitive Ca2+ release is likely to have a major influence on the generation and propagation of SWs.
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张弛振荡器是胃肠电活动的合适模型吗？
DOI：
10.1152/ajpgi.1989.256.2.g265
发表时间：
1989
期刊：
The American journal of physiology
影响因子：
--
作者：
Publicover,NG;Sanders,KM
通讯作者：
Sanders,KM
DOI：
10.1073/pnas.82.15.5231
发表时间：
1985-08
影响因子：
11.1
作者：
A. Somlyo;M. Bond;A. Somlyo;A. Scarpa
通讯作者：
A. Somlyo;M. Bond;A. Somlyo;A. Scarpa
激动剂诱导的胞质钙振荡源自单个肝细胞中的特定位点。
DOI：
--
发表时间：
1990
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Rooney,TA;Sass,EJ;Thomas,AP
通讯作者：
Thomas,AP
肝素抑制血管平滑肌中鸟嘌呤核苷酸诱导的肌醇 1,4,5-三磷酸依赖性钙释放，但不抑制独立钙释放。
DOI：
10.1016/s0006-291x(88)81141-0
发表时间：
1988
影响因子：
3.1
作者：
Kobayashi,S;Somlyo,AV;Somlyo,AP
通讯作者：
Somlyo,AP