Time-related changes in action potential and intracellular Ca localization of pregnant human myometrium in labor-regulating mechanism

分娩调节机制中妊娠人子宫肌层动作电位和细胞内 Ca 定位的时间相关变化

• 批准号: 12470351
• 负责人: KAWARABAYASHI Tatsuhiko
• 金额: $ 6.4万
• 依托单位: Fukuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12470351/
• 关键词: Myometrium; Pregnancy; Calcium channel; Cloning; Ca-channel subunit; ヒト子宮筋; 縦走筋; 輪走筋; 分娩; 電位依存性Caチャネル; Ca^<2+>チャンネル; β_2受容体

Myometrium has two types of voltage dependent calcium channels (VDCC). To clarify the physiological roles of T and L type calcium channels, mRNA expression in rat myometria during pregnancy was examined. The results were as follows: Rat myometrium showed increases in cell number and size in mid-pregnancy, and T type a1G, a1H and L type a1C of longitudinal muscle rapidly increased in the same stage, then gradually decreased to minimum levels just before the onset of labor and rapidly increased again during labor. It was suggested that L type channel might be main pathway during uterine contraction in labor and T type might play as pacemaker current, since the L type was expressed a couple of times more than T type. In circular muscle, both L and T type channels gradually increased from mid-pregnancy to term except for a1G. General expression of calcium channels but a1G was lower than longitudinal muscle, however elevated to high level in labor. Therefore, VDCC might be main calcium pathway to play as a triggering mechanism of excitation-contraction coupling both in longitudinal and circular muscles. In human myometrium, there were a1G and a1H but a1I. Then, cDNA library was prepared from human myometrial tissue, and PCR cloning of a1H subunit was performed by DNA polymerase (KodPlus) with high accuracy for enhancing. Sequence of the clone from myometrium was 780 bp longer from C-terminal than Perez-Reyes's result (Origin: Human heart). Moreover, two clones regarded as splicing variants, which were lost 11 aminoacids (33 base) at middle part of the long chain from C-terminal and lost 6 aminoacids (18 base) at middle part of the intracellular loop between domain III and IV, were obtained. Then, the same current reported previously could be recorded from BHK cell expressed these clones.

子宫肌层有两种电压依赖性钙通道(VDCC)。为阐明T型和L型钙通道的生理作用，对妊娠大鼠子宫肌层进行了基因表达检测。结果表明：妊娠中期大鼠子宫肌层细胞数量和大小增加，T型a1G、a1H和L型A1C型纵肌在同一时期迅速增加，临产前逐渐下降到最低水平，临产时又迅速增加。提示临产时子宫收缩的主要途径可能是L通道，而T型通道可能是起搏器电流，因为L通道比T型通道多表达几倍。在环肌中，除A1G外，L通道和T型通道从妊娠中期到足月逐渐增多。钙通道的普遍表达，但a1G低于纵肌，但在分娩时升高到较高水平。因此，VDCC可能是纵肌和环肌兴奋收缩偶联的主要触发机制。人子宫肌层中有a1G和a1H，但有a1I。然后，从人子宫肌层组织中制备cDNA文库，用DNA聚合酶(KodPlus)高精度地进行a1H亚基的聚合酶链式反应克隆。子宫肌层克隆的C端序列比Perez-Reyes的结果长780个碱基(来源：人心脏)。此外，还获得了两个被认为是剪接变异体的克隆，它们在C-末端的长链中部丢失了11个氨基酸(33个碱基)，在结构域III和IV之间的胞内环中部丢失了6个氨基酸(18个碱基)。然后，可以从表达这些克隆的BHK细胞中记录到与先前报道的相同的电流。

项目成果

Kobayashi,M.,Takeda,K.,Marata,S.,Kojima,M.,Akahane,M.,Inoue,Y.,Kitamura,K.,Kawarabayashi,T.: "Pharmacological characterization of KUR-124b, a selective uterine relaxant."J.Pharmacol.Exp.Ther.. (in press). (2001)

Kobayashi,M.、Takeda,K.、Marata,S.、Kojima,M.、Akahane,M.、Inoue,Y.、Kitamura,K.、Kawarabayashi,T.：“KUR-124b 的药理学特征，一种选择性的

Makino, I., Honda, K., Makino, Y., Okano, I., Kangawa, K., Kamiya, H., Shibata, K., Kawarabayashi, T.: "Phenotypic changes of adrenomedullin receptor components, RAMP2, and CRLR mRNA expression in cultured rat vascular smooth muscle cells"Biochem. Biophys

Makino, I.、Honda, K.、Makino, Y.、Okano, I.、Kangawa, K.、Kamiya, H.、Shibata, K.、Kawarabayashi, T.：“肾上腺髓质素受体成分 RAMP2 的表型变化，

Sonoda, M., Okamoto, F., Kajiya, H., Inoue, Y., Honjo, K,. Sumii, Y., Kawarabayashi, T., Okabe, K.: "Amino acid-permeable anion channels in early mouse embryos and their possible effects on cleavage"Biol. Repord.. 68. 947-953 (2003)

园田，M.，冈本，F.，梶谷，H.，井上，Y.，本庄，K，。

Makino, Y., Kobayashi, H., Kyono, K., Oshima, K., Kawarabayashi, T.: "Clinical results of fetal obstructive uropathy treated by vesicoamniotic shunting"Urology. 55. 118-122 (2000)

Makino, Y.、Kobayashi, H.、Kyono, K.、Oshima, K.、Kawarabayashi, T.：“膀胱羊膜分流术治疗胎儿梗阻性尿路病的临床结果”泌尿外科。

Sakakibara, T., Inoue, Y., Uzue, S., Tsukamoto, T., Kobayashi, M., Kojima, M., Akahane, M., Kitamura, K., Kawarabayashi, T.: "Diversity of inhibitory responses to β_2-stimulants shown by term-pregnant human myometria in vitro is partly dueto differences i

Sakakibara, T.、Inoue, Y.、Uzue, S.、Tsukamoto, T.、Kobayashi, M.、Kojima, M.、Akahane, M.、Kitamura, K.、Kawarabayashi, T.：“抑制反应的多样性体外足月妊娠人子宫肌层显示的 β_2 兴奋剂的差异部分是由于差异