Roles of Na+/Ca2+ exchanger isoforms NCX1 and NCX2 in motility in mouse ileum
详细信息 查看全文
- 作者：Kazuhiro Nishiyama ; Yasu-Taka Azuma…
- 关键词：Na+/Ca2+ exchanger ; Ileum ; Longitudinal smooth muscles ; Contraction ; Acetylcholine
- 刊名：Naunyn-Schmiedeberg's Archives of Pharmacology
- 出版年：2016
- 出版时间：October 2016
- 年：2016
- 卷：389
- 期：10
- 页码：1081-1090
- 全文大小：1,037 KB
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Biomedicine
Pharmacology and Toxicology
Neurosciences - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-1912
- 卷排序：389
文摘
The Na+/Ca2+ exchanger (NCX) is a plasma membrane transporter that is involved in regulating intracellular Ca2+ concentrations in various tissues. The physiological roles by which NCX influences gastrointestinal motility are incompletely understood, although its role in the heart, brain, and kidney has been widely investigated. In this study, we focused on the functions of the NCX isoforms, NCX1 and NCX2, in the motility of the ileum in the gastrointestinal tract. We investigated the response to electric field stimulation (EFS) in the longitudinal smooth muscle of the ileum obtained from wild-type mice (WT), NCX1-heterozygote knockout mice (NCX1 HET), NCX2 HET and smooth muscle-specific NCX1.3 transgenic mice (NCX1.3 Tg). EFS induced a phasic contraction that persisted during EFS and a tonic contraction that occurred after the end of EFS. We found that the amplitudes of the phasic and tonic contractions were significantly smaller in NCX2 HET, but not in NCX1 HET, compared to WT. Moreover, the magnitudes of acetylcholine (ACh)- and substance P (SP)-induced contractions of NCX2 HET, but not of NCX1 HET, were smaller compared to WT. In contrast, the amplitudes of the phasic and tonic contractions were greater in NCX1.3 Tg compared to WT. Similar to EFS, the magnitude of ACh-induced contraction was greater in NCX1.3 Tg than in WT. Taken together, our findings indicated that NCX1 and NCX2 play important roles in ileal motility and suggest that NCX1 and NCX2 regulate the motility in the ileum by controlling the sensitivity of smooth muscles to ACh and SP.