Adrenergic stimulation of rat resistance arteries affects Ca2+ sparks, Ca2+ waves, and Ca2+ oscillations
Adrenergic stimulation of rat resistance arteries affects Ca2+ sparks, Ca2+ waves, and Ca2+ oscillations
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DOI：
10.1152/ajpheart.2001.280.5.h2399
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发表时间：
2001-05-01
影响因子：
4.8
通讯作者：
Wier, WG
中科院分区：
文献类型：
--
作者：
Mauban, JRH;Lamont, C;Wier, WG
在α(1)-肾上腺素感受器激活过程中，使用共聚焦激光扫描显微镜和fluo - 4观察完整加压大鼠肠系膜小动脉单个平滑肌细胞（SMC）内局部和全细胞Ca2+瞬态。我们开发了一种方法来记录动脉直径变化过程中单个SMC内的Ca2+瞬态。三种不同类型的“Ca2+信号”受到肾上腺素能激活（激动剂：苯肾上腺素）的影响。首先，低水平的肾上腺素能刺激引起了非同步Ca2+瞬态。它们从一个起始点繁殖，然后充满细胞。其次，同步的、空间均匀的Ca2+瞬态，以前没有报道过，发生在较高水平的肾上腺素能刺激下，并在振荡血管舒张期间持续很长时间。最后，Ca2+火花在暴露于肾上腺素能激动剂期间发生频率缓慢下降。因此，肾上腺素能激活导致Ca2+火花频率的降低和异步波状Ca2+瞬态频率的增加，这两者都应该倾向于减小动脉直径。振荡血管运动与细胞[Ca2+]的空间均匀同步振荡有关，可能具有不同于异步传播的Ca2+瞬态的机制。
Confocal laser scanning microscopy and fluo 4 were used to visualize local and whole cell Ca2+ transients within individual smooth muscle cells (SMC) of intact, pressurized rat mesenteric small arteries during activation of alpha (1)-adrenoceptors. A method was developed to record the Ca2+ transients within individual SMC during the changes in arterial diameter. Three distinct types of "Ca2+ signals" were influenced by adrenergic activation (agonist: phenylephrine). First, asynchronous Ca2+ transients were elicited by low levels of adrenergic stimulation. These propagated from a point of origin and then filled the cell. Second, synchronous, spatially uniform Ca2+ transients, not reported previously, occurred at higher levels of adrenergic stimulation and continued for long periods during oscillatory vasomotion. Finally, Ca2+ sparks slowly decreased in frequency of occurrence during exposure to adrenergic agonists. Thus adrenergic activation causes a decrease in the frequency of Ca2+ sparks and an increase in the frequency of asynchronous wavelike Ca2+ transients, both of which should tend to decrease arterial diameter. Oscillatory vasomotion is associated with spatially uniform synchronous oscillations of cellular [Ca2+] and may have a different mechanism than the asynchronous, propagating Ca2+ transients.