Synergistic dual automaticity in sinoatrial node cell and tissue models.
Synergistic dual automaticity in sinoatrial node cell and tissue models.
复制标题
DOI：
10.1253/circj.cj-10-0265
复制
发表时间：
2010-10
期刊：
影响因子：
--
通讯作者：
Lin SF
中科院分区：
文献类型：
--
作者：
Zhang H;Joung B;Shinohara T;Mei X;Chen PS;Lin SF
传统上认为窦房结自律性的机制与膜离子电流有关。最近的证据表明，自发的肌浆网（SR）的钙循环也发挥了重要作用。我们对SAN细胞和一维组织模型进行了计算机模拟。在SAN细胞中，SR Ca ~（2+）循环广泛地调节窦性心率，从1.74 Hz到3.87 Hz。SR再充盈时间的缩短和SR Ca ~（2+）释放的增加是导致窦性心率加快的原因。然而，在快速SR Ca 2+循环下，L型Ca 2+电流（ICaL）降低导致不规则放电。当Ca ~（2+）循环受到抑制时，If和ICaT都有稳定起搏节律的作用，但ICaT的作用不如If。在一维水平，相邻细胞之间的电耦合对最早的起搏点位置的影响不大。主要起搏部位总是与SR Ca 2+循环速率最高的部位共定位，但转移到ICaL抑制较少的部位。SR Ca ~（2+）循环速率对窦性心率的调节是有效而广泛的。如果，ICaL和ICaT在保证SAN细胞节律性放电中起着不可或缺的作用。细胞内Ca ~（2+）动力学和膜电流共同决定了起搏点的位置，提示这种协同的双自律性不仅存在于单个SAN细胞中，也存在于组织水平。
The mechanism of sinoatrial node (SAN) automaticity is traditionally attributed to membrane ion currents. Recent evidence indicates spontaneous sarcoplasmic reticulum (SR) Ca2+ cycling also plays an important role. We performed computer simulation on SAN cell and 1D tissue model. In the SAN cells, SR Ca2+ cycling broadly modulated sinus rate from 1.74Hz to 3.87Hz. Shortening of the junctional SR refilling time and increase of SR Ca2+ release were responsible for sinus rate acceleration. However, under the fast SR Ca2+ cycling, decreased L-type Ca2+ current (ICaL) resulted in irregular firing. When Ca2+ cycling was suppressed, If and ICaT both acted to stabilize the pacemaker rhythm, but ICaT had less effect than If. At the 1D level, the electrical coupling between neighboring cells had little effect on the earliest pacemaker location. The leading pacemaking site always colocalized with the site with the highest SR Ca2+ cycling rate, but shifted to the site with less inhibited ICaL. The rate of SR Ca2+ cycling can effectively and broadly modulate the sinus rate. If, ICaL and ICaT play integral roles to guarantee SAN cell rhythmic firing. The leading pacemaker site is determined by intracellular Ca2+ dynamics and membrane currents, indicating the synergistic dual automaticity not only exists in single SAN cells, but also at the tissue level.
登录
查看更多内容
影响因子：
37.8
作者：
Joung B;Tang L;Maruyama M;Han S;Chen Z;Stucky M;Jones LR;Fishbein MC;Weiss JN;Chen PS;Lin SF
通讯作者：
Lin SF
影响因子：
3.3
作者：
Imai, Shinobu;Saito, Fumio;Hirayama, Atsushi
通讯作者：
Hirayama, Atsushi
影响因子：
3.2
作者：
Opthof, Tobias
通讯作者：
Opthof, Tobias
影响因子：
2.7
作者：
Shibata, N;Inada, S;Kodama, I
通讯作者：
Kodama, I
DOI：
10.1152/ajpheart.2001.280.5.h2103
发表时间：
2001-05-01
影响因子：
4.8
作者：
Verheule, S;van Kempen, MJA;Jongsma, HJ
通讯作者：
Jongsma, HJ