Increased colonic motility in a rat model of irritable bowel syndrome is associated with up-regulation of L-type calcium channels in colonic smooth muscle cells
Increased colonic motility in a rat model of irritable bowel syndrome is associated with up-regulation of L-type calcium channels in colonic smooth muscle cells
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DOI：
10.1111/j.1365-2982.2009.01467.x
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发表时间：
2010-05-01
影响因子：
3.5
通讯作者：
Bian, Z. -X.
中科院分区：
文献类型：
--
作者：
Zhang, M.;Leung, F. -P.;Bian, Z. -X.
目的探讨肠易激综合征（irritable bowel syndrome，IBS）大鼠模型L型钙通道表达上调与肠动力障碍的关系。方法雄性SD大鼠出生后2-14天进行新生儿母体分离（NMS）或正常处理（NH），体重250-300 g。在器官浴系统中研究结肠平滑肌收缩。应用免疫荧光和Western印迹技术研究了大鼠结肠平滑肌L型钙通道α（1c）亚单位的表达。细胞内钙离子浓度采用激光共聚焦荧光显微镜对酶法分离的单个结肠平滑肌细胞的[Ca 2 +]（i）进行研究。结果避水应激（WAS）1h时粪粒明显增加;自发收缩和Bay K 8644诱发收缩的幅度与NH组相比，NMS组大鼠血浆中KC 1（10 nm-1 μ m）、KC 1（10-60 nm）和ACh（100 nm-10 μ m）含量明显增加。[Ca2在NMS大鼠肌细胞中，Bay K 8644（1 μ m）、KCl（40 μ m）和ACh（10 μ m）诱导的+]i显著高于NH大鼠。NMS大鼠结肠平滑肌α（1c）蛋白表达较NH大鼠显著上调。结论NMS可导致结肠L型钙通道表达上调，从而导致结肠运动障碍。我们的研究结果提供了直接的证据，以帮助理解慢性应激诱导的肠易激综合征结肠动力障碍的潜在机制。
ObjectiveThis paper aimed to investigate the relationship between up-regulation of L-type calcium channels and altered motility disorder in a rat model of irritable bowel syndrome (IBS).MethodsMale Sprague-Dawley rats were subjected to neonatal maternal separation (NMS) from postnatal day 2-14 or normal handling (NH), and used when weighted 250-300 g. Colonic smooth muscle contractions was studied in an organ bath system. L-type Ca2+ channel alpha(1c) subunit expression in smooth muscles from rat colon were studied by immunofluorescence and Western blotting analysis. The intracellular calcium concentration ([Ca2+](i)) of enzymatically isolated single colonic smooth muscle cell was studied with laser confocal fluorescent microscopy.ResultsThe fecal pellets during 1 h water avoidance stress (WAS) were significantly increased; the amplitude of spontaneous contractions and contractions induced by Bay K 8644 (10 nm-1 mu m), KCl (10-60 mm) and ACh (100 nm-10 mu m) were significantly increased in NMS rats, when comparing with that of NH rats. [Ca2+]i induced by Bay K 8644 (1 mu m), KCl (40 mm), and ACh (10 mu m) significantly increased in muscle cells of NMS rats than NH rats. Further, alpha(1c) protein expression was significantly up-regulated in colonic smooth muscle of NMS rats than NH rats.ConclusionThese results suggest that NMS lead to up-regulation of L-type Ca2+ channels expression in the colon, which contributes to the colonic motility disorder. Our findings provide direct evidence to help understanding the underlying mechanism of chronic stress-induced colonic motility disorder in IBS.