Cellular Mechanisms and Regulation of Intestinal Potassium Transport

肠道钾转运的细胞机制和调节

• 批准号: 12470008
• 负责人: SUZUKI Yuichi
• 金额: $ 8.13万
• 依托单位: University of Shizuoka
• 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-12470008/
• 关键词: potassium absorption; potassium secretion; intestinal K^+ transport; aldosterone; ouabain; short-circuit current; epithelial transport; アルドステロン; 小腸; 大腸; K吸収; H, K-ATpase; カリウム吸収; カリウム排泄; ナトリウム排泄; 塩素排泄; 予測制御; Kイオン吸収; 一方向性フラックス; 能動輸送; 回腸

Potassium is one of the most abundant cation in the body, and plays a variety of physiological functions. This study aimed at elucidating the cellular mechanisms and regulation of intestinal K^+ transport. The results showed that; (1)in human study, urinary potassium excretion after potassium intake or potassium injection was accompanied by an increase in blood K^+, (2)in rat study using polyethylene glycol as an non-absorbable marker, ingested K^+ is absorbed mostly in the proximal jejunum probably mainly by passive diffusion. We have also demonstrated in in vitro studies that (1)active K^+ absorption occurs in the mouse ileum, (2)both active absorption and secretion of K^+ occur in the mouse distal colon. The active K^+ secretion in the distal colon was enhanced by beta-adrenergic agonists and dietary K load. In addition, the colonic H,K-ATPase responsible for active K^+ absorption was inhibited by a variety of ouabain-like substances. Finally, the colonic K^+ secretion was enhanced by aldosterone while the K^+ absorption was not enhanced.

钾是体内含量最丰富的阳离子之一，发挥多种生理功能。本研究旨在阐明肠道 K^+ 转运的细胞机制和调节。结果表明； (1)在人体研究中，摄入钾或注射钾后尿钾排泄伴随着血液中K^+的增加，(2)在使用聚乙二醇作为不可吸收标记物的大鼠研究中，摄入的K^+大部分被吸收在近端空肠中可能主要通过被动扩散。我们还在体外研究中证明，（1）K^+的主动吸收发生在小鼠回肠中，（2）K^+的主动吸收和分泌都发生在小鼠远端结肠中。 β-肾上腺素能激动剂和膳食钾负荷可增强远端结肠的活性 K^+ 分泌。此外，负责活性K^+吸收的结肠H,K-ATP酶被多种哇巴因样物质抑制。最后，醛固酮增强结肠K^+分泌，但K^+吸收没有增强。

项目成果

Inagaki, E, Kawamata, K, Suzuki, Y.: "In vitro potassium transport in the mouse small intestine"Japanese Journal of Physiology. 52. 515-520 (2002)

Inagaki，E，Kawamata，K，Suzuki，Y.：“小鼠小肠中的体外钾转运”日本生理学杂志。

Inagaki, E., Kawamata, K., Suzuki, Y: "In vitro potassium transport in the mouse small intestine"Japanese Journal of Physiololgy. 52. 515-520 (2002)

Inagaki，E.，Kawamata，K.，Suzuki，Y：“小鼠小肠中的体外钾转运”日本生理学杂志。

Inagaki, E., Kawamata, K., Suzuki, Y: "In vitro potassium transport in the mouse small intestine"Japanese Journal of Physiology. 52. 515-520 (2002)

Inagaki，E.，Kawamata，K.，Suzuki，Y：“小鼠小肠中的体外钾转运”日本生理学杂志。