Enhanced colonic Na+ absorption in cystic fibrosis mice versus normal mice
| Autor: | Barbara R. Grubb, R. C. Boucher |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Male
medicine.medical_specialty Pancreatic disease Cystic Fibrosis Colon Physiology medicine.drug_class Absorption (skin) Cystic fibrosis Absorption Amiloride Mice chemistry.chemical_compound Reference Values Physiology (medical) Internal medicine medicine Animals Intestinal Mucosa Aldosterone Infusion Pumps Hepatology biology Ussing chamber Chemistry Sodium Gastroenterology medicine.disease Cystic fibrosis transmembrane conductance regulator Electrophysiology Endocrinology Barium Mineralocorticoid biology.protein Female medicine.drug |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 272:G393-G400 |
| ISSN: | 1522-1547 0193-1857 |
| DOI: | 10.1152/ajpgi.1997.272.2.g393 |
| Popis: | Because there are reports that electrogenic Na+ absorption is increased in colonic epithelia of cystic fibrosis (CF) subjects, we tested whether amiloride-sensitive Na+ absorption was increased in the colonic epithelia of CF mice compared with normal mice on high- or low-Na+ diets. When mice consumed a diet high in Na+, none of the colonic regions (distal colon, proximal colon, or cecum) from either group of mice exhibited an amiloride-sensitive short-circuit current (Isc). However, when mice were placed on a low-Na+ diet for 2 wk, all three intestinal regions from the CF mice exhibited a significant response to amiloride (P < or = 0.05). In contrast, normal mice on the low-Na+ diet exhibited an amiloride-sensitive Isc that was smaller and only significant in the cecum and distal colon. Measurement of plasma aldosterone levels revealed that the CF mice on the low-Na+ diet had significantly greater aldosterone levels than similarly treated controls [8,906 +/- 1,039 (n = 14) vs. 5,243 +/- 1,410 pg/ml (n = 14), respectively]. When mice were infused with a constant dose of aldosterone (1 microg x g(-1) x day(-1)) for 7 days, the distal colon of the CF mice still had a significantly greater amiloride-sensitive Isc than did the normal distal colon. If the presence of CF transmembrane conductance regulator (CFTR) down-regulates Na+ absorption in the colonic tissue from normal mice, our data suggest that at least some CFTR may be colocalized with the Na+ channel. Alternatively, other factors may be involved. |
| Databáze: | OpenAIRE |
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