Incidence of myoendothelial gap junctions in the proximal and distal mesenteric arteries of the rat is suggestive of a role in endothelium-derived hyperpolarizing factor-mediated responses.
Incidence of myoendothelial gap junctions in the proximal and distal mesenteric arteries of the rat is suggestive of a role in endothelium-derived hyperpolarizing factor-mediated responses.
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DOI：
10.1161/01.res.86.3.341
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发表时间：
2000-02
影响因子：
20.1
通讯作者：
S. Sandow;C. Hill
中科院分区：
文献类型：
--
作者：
S. Sandow;C. Hill
虽然内皮源性超极化因子（EDHF）的化学性质仍然难以捉摸，电生理证据存在平滑肌细胞和内皮细胞之间的电通信，表明超极化的电紧张性传播可能解释了未能确定一个单一的化学因子EDHF。然而，肌内皮间隙连接或电耦合位点的解剖学证据是罕见的。在本研究中，连续切片电子显微镜和重建技术已被用来检查在近端和远端肠系膜动脉的大鼠EDHF反应的发生率不同。在肠系膜动脉中发现肌内皮缝隙连接非常小，大多数直径<100 nm。此外，与该动脉床的近端区域相比，它们在远端更常见。相邻内皮细胞之间的五层间隙连接要大得多，常见于近端和远端肠系膜动脉。后者的连接经常被发现附近的肌内皮细胞间隙连接。这些结果提供了第一个证据的存在的网站之间的电通信内皮细胞和平滑肌细胞在肠系膜血管床。此外，这些网站的相对发病率表明，可能有一个EDHF的活动和肌内皮缝隙连接的存在之间的关系。
Although the chemical nature of endothelium-derived hyperpolarizing factor (EDHF) remains elusive, electrophysiological evidence exists for electrical communication between smooth muscle cells and endothelial cells suggesting that electrotonic propagation of hyperpolarization may explain the failure to identify a single chemical factor as EDHF. Anatomical evidence for myoendothelial gap junctions, or the sites of electrical coupling, is, however, rare. In the present study, serial-section electron microscopy and reconstruction techniques have been used to examine the incidence of myoendothelial gap junctions in the proximal and distal mesenteric arteries of the rat where EDHF responses have been reported to vary. Myoendothelial gap junctions were found to be very small in the mesenteric arteries, the majority being <100 nm in diameter. In addition, they were significantly more common in the distal compared with the proximal regions of this arterial bed. Pentalaminar gap junctions between adjacent endothelial cells were much larger and were common in both proximal and distal mesenteric arteries. These latter junctions were frequently found near the myoendothelial gap junctions. These results provide the first evidence for the presence of sites for electrical communication between endothelial cells and smooth muscle cells in the mesenteric vascular bed. Furthermore, the relative incidence of these sites suggests that there may be a relationship between the activity of EDHF and the presence of myoendothelial gap junctions.