Role of ryanodine receptor channels in Ca2+ oscillations of porcine tracheal smooth muscle
Role of ryanodine receptor channels in Ca2+ oscillations of porcine tracheal smooth muscle
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DOI：
10.1152/ajplung.1997.272.4.l659
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发表时间：
1997-04-01
影响因子：
4.9
通讯作者：
Sieck, GC
中科院分区：
文献类型：
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作者：
Kannan, MS;Prakash, YS;Sieck, GC
乙酰胆碱 (ACh) 在猪气管平滑肌 (TSM) 细胞中诱导重复的、传播的细胞内 Ca2+ 浓度 ([Ca2+](i)) 振荡。使用实时共聚焦显微镜，我们检查了肌浆网 (SR) Ca2+ 通过肌醇 1,4,5-三磷酸 (IP3) 受体和兰尼碱受体 (RyR) 通道释放在 ACh 诱导的 [Ca2+](i) 振荡中的作用。在 β-七叶皂苷透化的 TSM 细胞中，在 GTP 存在的情况下暴露于 ACh 也会导致 [Ca2+](i) 振荡。 [Ca2+](i) 振荡不能单独由 IP3 引发；然而，观察到 [Ca2+](i) 升高。在持续的 [Ca2+](i) 振荡期间，暴露于肝素（IP3 受体拮抗剂）会导致振荡频率减慢，但不会完全抑制。相反，钌红（一种 RyR 拮抗剂）完全消除了 ACh 诱导的 [Ca2+](i) 振荡。 TSM mRNA 的逆转录酶-聚合酶链反应证明了 RyR 的 RyR-2 和 RyR-3 亚型的表达。这些结果表明，SR Ca2+ 通过 RyR 通道释放对于猪 TSM 细胞中 ACh 诱导的 [Ca2+](i) 振荡至关重要。
Acetylcholine (ACh) induces repetitive, propagating intracellular Ca2+ concentration ([Ca2+](i)) oscillations in porcine tracheal smooth muscle (TSM) cells. Using real-time confocal microscopy, we examined the role of sarcoplasmic reticulum (SR) Ca2+ release through inositol 1,4,5-trisphosphate (IP3) receptor and ryanodine receptor (RyR) channels in ACh-induced [Ca2+](i) oscillations. In beta-escin permeabilized TSM cells, exposure to ACh in the presence of GTP also resulted in [Ca2+](i) oscillations. [Ca2+](i) oscillations could not be initiated by IP3 alone; however, an elevation of [Ca2+](i) was observed. During ongoing [Ca2+](i) oscillations, exposure to heparin, an IP3 receptor antagonist, caused a slowing of oscillation frequency but not complete inhibition. In contrast, ruthenium red, a RyR antagonist, completely abolished ACh-induced [Ca2+](i) oscillations. Reverse transcriptase-polymerase chain reaction of TSM mRNA demonstrated the expression of RyR-2 and RyR-3 isoforms of the RyR. These results indicate that SR Ca2+ release through RyR channels is critical for ACh-induced [Ca2+](i) oscillations in porcine TSM cells.