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The study of cell membrane ion channels involving in automaticity of human uterine smooth muscle cells.

细胞膜离子通道参与人子宫平滑肌细胞自律性的研究。

基本信息

批准号：
14571596
负责人：
INOUE Yoshihito
金额：
$ 1.34万
依托单位：
Fukuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14571596/
关键词：
uterine smooth muscle.hyperpolarization-activated inward current T-type calcium channel voltage clamp α1 subunit ヒト子宮平滑筋 T-type Ca^<2+> channel 収縮頻度調整 α1 subunit 過分極誘発性内向き電流単離細胞

项目摘要

The aim of this study was to find the membrane channels which involves in automaticity of human myometrium. For the beginning, we tried to record hyperpolarization-induced inward current which was recorded in rat myometrium using patch clamp methods, but it failed. So we evaluated the difference in the expression of mRNA of two types of calcium channels between longitudinal and circular muscle layer of rat mayometrium during pregnancy. Changes in the expressions of the mRNA encoding L-type (α1C) and T-type (α1G, α1H, and all) calcium channels in longitudinal and circular smooth muscle cells of the rat myometrium were examined using a comparative kinetic RT/PCR method. During the course of pregnancy, α1C mRNA expression showed an N-shaped change in longitudinal muscle, but simply increased after mid pregnancy in circular muscles. The mRNAs for α1G and α1H, but not that for all, were expressed in both longitudinal and circular smooth muscle. In longitudinal muscle, the changes in α1H mRNA was similar to that in α1C mRNA during gestation, but the expression of α1G mRNA changed significantly only at term (day 22). In circular muscle, α1H mRNA expression was stable at any stage during pregnancy, but α1G mRNA significantly increased on day 15 and at term. No relationship was observed between voltage-dependent calcium-channel mRNA expressions and either proliferation or hypertrophy of circular muscle during pregnancy. These results show, (a)that during pregnancy, the expression levels of L-type channels change dynamically, and it may contribute directly to the regulation of cell excitability, and (b)that the T-subtype that increases during pregnancy differs between longitudinal and circular muscle cells, although their functions remain unclear.

本研究的目的是寻找参与人子宫肌层自律性的膜通道。我们首先尝试用膜片钳方法记录大鼠子宫肌层的超极化内向电流，但未能成功。因此，我们评估了两种类型的钙通道的mRNA表达的差异，在纵向和环形肌层的大鼠妊娠期子宫内膜。用比较动力学RT/PCR方法检测大鼠子宫平滑肌细胞L型（α1C）和T型（α1G、α1H和all）钙通道mRNA表达的变化。在妊娠过程中，纵肌α1C mRNA表达呈“N”形变化，而环肌α1C mRNA表达在妊娠中期后呈单纯性增加。α1G和α1H的mRNA在纵、环平滑肌中均有表达，但并非全部表达。在纵行肌中，α 1 H mRNA和α 1 C mRNA在妊娠期间的变化趋势相似，而α 1 G mRNA的表达仅在足月（22 d）时才有显著变化。在环行肌中，α 1 H mRNA在妊娠各期均稳定表达，而α 1 G mRNA在妊娠15 d和足月时显著升高。电压依赖性钙通道mRNA的表达与妊娠期环行肌的增生或肥大之间没有关系。这些结果表明，（a）在怀孕期间，L型通道的表达水平动态变化，它可能直接有助于细胞兴奋性的调节，和（B）在怀孕期间增加的T亚型在纵肌和环肌细胞之间是不同的，尽管它们的功能尚不清楚。