Effect of nitric oxide on electrolyte transport across the porcine proximal colon
| Autor: | B. Garz, Jörg R. Aschenbach, Gotthold Gäbel, F. Ahrens |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Nitroprusside
Quinidine Potassium Channels Colon Swine Physiology Inorganic chemistry In Vitro Techniques S-Nitroso-N-Acetylpenicillamine Nitric Oxide Biochemistry Epithelium Ion Channels Permeability Nitric oxide Electrolytes chemistry.chemical_compound Endocrinology Chlorides medicine Animals Mannitol Nitric Oxide Donors Ecology Evolution Behavior and Systematics Ion transporter Ion Transport Tetraethylammonium Ussing chamber Sodium Electric Conductivity Intracellular Membranes Potassium channel chemistry Paracellular transport Potassium Biophysics Animal Science and Zoology Sodium nitroprusside medicine.drug |
| Zdroj: | Journal of Comparative Physiology B. 173:177-186 |
| ISSN: | 1432-136X 0174-1578 |
| DOI: | 10.1007/s00360-002-0310-z |
| Popis: | The effect of nitric oxide (NO) on ion transport in the porcine proximal colon was investigated in slide-stripped epithelia mounted in Ussing chambers. The serosal addition of the NO-donors sodium nitroprusside (SNP, 0.5 mM) or S-nitroso-N-acetylpenicillamine (SNAP, 0.5 mM) induced a steep increase of short-circuit current ( I sc). The stimulatory effect of SNP on I sc could not be blocked by piroxicam or tetrodotoxin. Potassium channel inhibitors (quinidine, tetraethylammonium or barium) added serosally reduced the SNP- or SNAP-induced increases of I sc. In chloride-free solutions, the SNP-induced increase of I sc was smaller than in chloride-containing solutions. Cl− and Na+ flux measurements demonstrated that SNP diminished Cl− and Na+ net absorption. Pre-treatment with barium was able to block the inhibitory effect of SNP on NaCl net absorption totally. NO effects on paracellular pathways were assessed by measuring flux rates of [14C]-D-mannitol. SNP did not change unidirectional D-mannitol flux rates. In conclusion, NO inhibits NaCl net absorption in the proximal colon of pigs by acting directly on the enterocyte. The antiabsorptive (and/or prosecretory) effect of NO depends on a functional basolateral potassium conductance. |
| Databáze: | OpenAIRE |
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