Ca2+ phase waves: a basis for cellular pacemaking and long‐range synchronicity in the guinea‐pig gastric pylorus
Ca2+ phase waves: a basis for cellular pacemaking and long‐range synchronicity in the guinea‐pig gastric pylorus
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Ca2+相波：豚鼠胃幽门细胞起搏和远程同步性的基础
DOI：
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
M. Imtiaz
中科院分区：
文献类型：
--
作者：
D. Helden;M. Imtiaz
钙离子成像和多个微电极记录程序用于研究豚鼠胃幽门环肌层单束条带的慢波样电节律性。“慢波”（SWs）由起搏器和再生组件组成，这两种电位都由更基本的事件组成，这些事件被称为自发瞬态去极化（STDs）或单一电位。std和SW的起搏器和再生电位分别表现出相关的局部和分布Ca2+瞬态。Ca2+瞬态通常在细胞区域较大，显示出较高的基础Ca2+指示剂相关荧光，典型的区域可能包含肌内间质细胞Cajal （ICCIM）。节律性的出现源于性传播疾病引起的起搏器Ca2+瞬态和电位，这些事件表现出相当大的空间同步性。对节律性较弱的条带施用乙酰胆碱，可显著增强其SW同步性。SWs和潜在的Ca2+增加表现出非常高的“表观传导速度”（“CVs”）数量级大于顺序传导Ca2+波。细胞间连接或肌醇1,4,5 -三磷酸受体（IP3R）介导的条状Ca2+储存释放的中心中断导致两端的SWs相互独立运行，这与基于耦合振荡器的机制一致。中枢抑制存储需要比连接抑制更广泛的封锁区域，这表明存储是电压耦合的。使用传统存储阵列模型进行的模拟，现在包括与IP3R介导的Ca2+释放耦合的去极化，预测了实验结果。膜电压和Ca2+释放之间的联系为存储体作为强耦合振荡器相互作用提供了一种手段，导致Ca2+相波和相关起搏器电位的出现。这种分布式起搏器触发再生Ca2+释放并产生SWs。
Ca2+ imaging and multiple microelectrode recording procedures were used to investigate a slow wave‐like electrical rhythmicity in single bundle strips from the circular muscle layer of the guinea‐pig gastric pylorus. The ‘slow waves’ (SWs) consisted of a pacemaker and regenerative component, with both potentials composed of more elementary events variously termed spontaneous transient depolarizations (STDs) or unitary potentials. STDs and SW pacemaker and regenerative potentials exhibited associated local and distributed Ca2+ transients, respectively. Ca2+ transients were often larger in cellular regions that exhibited higher basal Ca2+ indicator‐associated fluorescence, typical of regions likely to contain intramuscular interstitial cells of Cajal (ICCIM). The emergence of rhythmicity arose through entrainment of STDs resulting in pacemaker Ca2+ transients and potentials, events that exhibited considerable spatial synchronicity. Application of ACh to strips exhibiting weak rhythmicity caused marked enhancement of SW synchronicity. SWs and underlying Ca2+ increases exhibited very high ‘apparent conduction velocities’ (‘CVs’) orders of magnitude greater than for sequentially conducting Ca2+ waves. Central interruption of either intercellular connectivity or inositol 1,4,5‐trisphosphate receptor (IP3R)‐mediated store Ca2+ release in strips caused SWs at the two ends to run independently of each other, consistent with a coupled oscillator‐based mechanism. Central inhibition of stores required much wider regions of blockade than inhibition of connectivity indicating that stores were voltage‐coupled. Simulations, made using a conventional store array model but now including depolarization coupled to IP3R‐mediated Ca2+ release, predicted the experimental findings. The linkage between membrane voltage and Ca2+ release provides a means for stores to interact as strongly coupled oscillators, resulting in the emergence of Ca2+ phase waves and associated pacemaker potentials. This distributed pacemaker triggers regenerative Ca2+ release and resultant SWs.
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影响因子：
56.9
作者：
HAROOTUNIAN, AT;KAO, JPY;TSIEN, RY
通讯作者：
TSIEN, RY
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
影响因子：
56.9
作者：
ALLBRITTON, NL;MEYER, T;STRYER, L
通讯作者：
STRYER, L
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