How Structure, Ca Signals, and Cellular Communications Underlie Function in Precapillary Arterioles
How Structure, Ca Signals, and Cellular Communications Underlie Function in Precapillary Arterioles
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DOI：
10.1161/circresaha.109.202960
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发表时间：
2009-10-09
影响因子：
20.1
通讯作者：
Burdyga, Theodor
中科院分区：
文献类型：
--
作者：
Borisova, Lyudmyla;Wray, Susan;Burdyga, Theodor
原理：毛细血管前小动脉控制流向组织的血流，其正确功能至关重要。然而，它们的小尺寸限制了研究，并且关于它们的内皮细胞和肌肉细胞中的钙信号以及这些钙信号与功能的关系知之甚少。目的：我们旨在研究这些小血管是否在结构和钙信号方面特化。利用原位共聚焦成像技术，我们研究了超微结构，输尿管和输精管毛细血管前小动脉钙信号与收缩协调。我们比较了数据，从一个小肠系膜动脉。在毛细血管前小动脉中，1个肌细胞覆盖约10 μ m的长度，并且该单个细胞的收缩可以减小该段的直径。在肠系膜动脉中，需要20多个肌细胞。在毛细血管前小动脉中，Ca信号仅由肌浆网通过肌醇1，4，5-三磷酸诱导的Ca释放而产生，而不通过ryanodine受体。激动剂诱导的Ca信号不需要Ca进入细胞，不扩散或与相邻细胞同步，并且不受内皮刺激的影响，从而允许局部控制。这与肠系膜动脉，钙进入和ryanodine受体是重要的和刺激的内皮细胞抑制肌细胞钙信号和contractions.Conclusions：这些数据揭示了结构和信号的专业化的基础上如何局部调节血流，微循环控制提供了新的见解，并提供了一个框架来解释其对疾病的脆弱性。(Circ Res. 2009; 105：803 - 810）。
Rationale: Precapillary arterioles control blood flow to tissues and their correct function is vital. However, their small size has limited study and little is known concerning the calcium signals in their endothelial and muscle cells and how these relate to function.Objective: We aimed to investigate whether these small vessels are specialized in terms of structure and calcium signaling.Methods and Results: Using in situ confocal imaging we have studied the ultrastructure, Ca signaling and coordination of contraction in precapillary arterioles in ureter and vas deferens. We have compared the data to that from a small mesenteric artery. In the precapillary arteriole, 1 myocyte covers a approximate to 10-mu m length, and contraction of this single cell can decrease the diameter of this segment. In the mesenteric artery, more than 20 myocytes are required for this. In the precapillary arteriole, Ca signals arise solely from Ca release from the sarcoplasmic reticulum through inositol 1,4,5-trisphosphate-induced Ca release and not via ryanodine receptors. Agonist-induced Ca signals do not require Ca entry into the cell, do not spread or synchronize with neighboring cells, and are unaffected by endothelial stimulation, thereby allowing local control. This contrasts with the mesenteric artery, where Ca entry and ryanodine receptors are important and stimulation of the endothelium inhibits myocyte Ca signals and contraction.Conclusions: These data reveal the structural and signaling specializations underlying how blood flow is locally regulated, provide new insight into control of microcirculation, and provide a framework to explain its vulnerability to disease. (Circ Res. 2009; 105: 803-810.)