Evidence for signaling via gap junctions from smooth muscle to endothelial cells in rat mesenteric arteries:: possible implication of a second messenger
Evidence for signaling via gap junctions from smooth muscle to endothelial cells in rat mesenteric arteries:: possible implication of a second messenger
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DOI：
10.1016/j.ceca.2004.11.004
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发表时间：
2005-04-01
期刊：
影响因子：
4
通讯作者：
Meister, JJ
中科院分区：
文献类型：
--
作者：
Lamboley, M;Pittet, P;Meister, JJ
我们使用共聚焦显微镜在细胞水平上研究了大鼠肠系膜动脉条中的异细胞通讯。用Fluo-4负载血管内皮细胞(ECs)和血管内皮细胞(ECs)，观察不同细胞群内钙离子的变化。用高K+溶液和苯肾上腺素刺激SMC收缩。根据血管收缩药浓度的不同，在相邻的血管内皮细胞中观察到[Ca~(2+)](I)升高后，内皮细胞5-11 S的细胞内钙浓度([Ca~(2+)](I))也随之升高。这一时间间隔表明，SMC和ECs之间通过缝隙连接进行了化学耦合。作为潜在的化学介体，我们研究了Ca~(2+)或1，4，5-三磷酸肌醇(IP3)。首先，加入磷脂酶C抑制剂U-73122以阻止IP_3的产生，以响应[Ca~(2+)](I)的增加。在高K+溶液中，所有血管内皮细胞[Ca~(2+)](I)呈整体同步升高，而内皮细胞未见[Ca~(2+)](I)变化。2-氨基乙氧基二苯基硼酸酯(IP3诱导的钙释放的阻断剂)使闪烁的内皮细胞数减少75+/-3%(n=6)。通过添加间隙连接解偶联剂棕榈油酸，闪光EC的数量也同样减少。因此，我们的结果表明，通过缝隙连接从SMC到ECs的异质细胞通讯可能是通过扩散，可能是IP3。(C)2004爱思唯尔有限公司。保留所有权利。
We investigated heterocellular communication in rat mesenteric arterial strips at the cellular level using confocal microscopy. To visualize Ca2+ changes in different cell populations, smooth muscle cells (SMCs) were loaded with Fluo-4 and endothelial cells (ECs) with Fura red. SMC contraction was stimulated using high K+ solution and Phenylephrine. Depending on vasoconstrictor concentration, intracellular Ca2+ concentration ([Ca2+](i)) increased in a subpopulation of ECs 5-11 s after a [Ca2+](i) rise was observed in adjacent SMCs. This time interval suggests chemical coupling between SMCs and ECs via gap junctions. As potential chemical mediators we investigated Ca2+ or inositol 1,4,5-trisphosphate (IP3). First, phospholipase C inhibitor U-73122 was added to prevent IP3 production in response to the [Ca2+](i) increase in SMCs. In high K+ solution, all SMCs presented global and synchronous [Ca2+](i) increase, but no [Ca2+](i) variations were detected in ECs. Second, 2-aminoethoxydiphenylborate, an inhibitor of IP3-induced Ca2+ release, reduced the number of flashing ECs by 75 +/- 3% (n = 6). The number of flashing ECs was similarly reduced by adding the gap junction uncoupler palmitoleic acid. Thus, our results suggest a heterocellular communication through gap junctions from SMCs to ECs by diffusion, probably of IP3. (C) 2004 Elsevier Ltd. All rights reserved.