Abstract
To more clearly define the role of the transepithelial electrical potential difference (V(m→s)), potassium permeability, and sodium potassium pump rate in transcellular potassium transport by isolated turtle colon, we measured transmural potassium fluxes under open-circuit conditions in the presence and absence of putative blockers of potassium transport: amiloride and barium. The results were consistent with the notion that V(m→s) is a major determinant of cellular potassium secretion, whereas active potassium absorption is insensitive to changes in V(m→s). These observations suggest that 'coupling' between colonic sodium absorption and potassium secretion in vivo could be due primarily to the effect of the lumen negative V(m→s) on transcellular secretory potassium flow. Amiloride-induced inhibition of potassium secretion appeared to be due to the reductions in V(m→s) and sodium-potassium pump rate that accompanied the inhibition of active sodium absorption.
Original language | English |
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Pages (from-to) | C26-C32 |
Journal | American Journal of Physiology - Cell Physiology |
Volume | 247 |
Issue number | 1 |
DOIs | |
State | Published - 1984 |
Externally published | Yes |
ASJC Scopus Subject Areas
- Physiology (medical)
Keywords
- Active Transport
- Amiloride
- Potassium Secretion
- Pseudemys scripta
- Amiloride / pharmacology
- Anmals
- Barium / pharmacology
- Biological Transport, Active
- Cell Membrane Pereability
- Colon / drug effects
- Colon / metabolism*
- Ion Channels / drug effects
- Ion Channels / physiology
- Membrane Potentials
- Potassium / antagonists & inhibitors
- Potassium / metabolism*
- Sodium / metabolism
- Trutles / metabolism*
- Ion Channels
- Barium
- Sodium
- Potassium
Disciplines
- Medical Cell Biology
- Medical Neurobiology
- Medical Physiology
- Neurosciences
- Physiological Processes