2002 Fiscal Year Final Research Report Summary
Cellular Mechanisms and Regulation of Intestinal Potassium Transport
| Project/Area Number |
12470008
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General physiology
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| Research Institution | University of Shizuoka |
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Principal Investigator |
SUZUKI Yuichi University of Shizuoka, School of Food and Nutritional Sciences, Professor, 食品栄養科学部, 教授 (50091707)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Hisayoshi University of Shizuoka, School of Food and Nutritional Sciences, Instructor, 食品栄養科学部, 助手 (40238118)
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| Project Period (FY) |
2000 – 2002
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| Keywords | potassium absorption / potassium secretion / intestinal K^+ transport / aldosterone / ouabain / short-circuit current / epithelial transport / アルドステロン |
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| Research Abstract |
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.
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