Sodium and chloride transport in the large intestine of potassium-loaded rats

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · Am. J. Physiol.; (United States)

OSTI ID:6280909

Budinger, M E; Foster, E S; Hayslett, J P; Binder, H J

Increased dietary potassium (potassium loading) induces several adaptive changes in colonic function, including increased potential dependent potassium secretion, active potassium secretion, and Na-K-ATPase activity, but does not alter net sodium absorption in vivo. To establish whether potassium loading stimulates active sodium transport, unidirectional, net sodium, and chloride fluxes were determined under voltage-clamp conditions across isolated rat distal colonic mucosa. In normal animals net sodium flux (J/sub net/sup Na/), net chloride flux (J/sub net/sub Cl/) and short-circuit current (I/sub sc/) were 6.1 +/- 1.1, 8.4 +/-1.0, and 0.7 +/- 0.1 eq h cm S, respectively; potassium loading significantly increased J/sub net/sup Na/ and I/sup sc/ by 4.9 +/- 1.4 and 3.5 +/- 0.7 eq h cm S, respectively, without changing J/sub net/sup Na/ and I/sub sc/ produced by potassium loading. In Cl-free Ringer solution in normal animals J/sub net/sup Na was reduced to 0.6 +/- 0.3 eq h cm S. Potassium loading produced identical increases in J/sub net/sup Na/ and I/sub sc/, which were also completely inhibited by 0.1 mM amiloride. These studies establish that potassium loading induces amiloride-sensitive electrogenic sodium absorption without affecting electroneutral sodium-chloride absorption.

• Research Organization: Yale Univ. School of Medicine, New Haven, CT
• OSTI ID: 6280909
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 251:2; ISSN AJPHA
• Country of Publication: United States
• Language: English

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551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BODY
CHARGED PARTICLES
CHLORINE 36
CHLORINE ISOTOPES
DIET
DIGESTIVE SYSTEM
ELECTRON CAPTURE RADIOISOTOPES
GASTROINTESTINAL TRACT
INTESTINAL ABSORPTION
INTESTINES
IONS
ISOTOPES
LARGE INTESTINE
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
NUTRITIONAL DEFICIENCY
ODD-ODD NUCLEI
ORGANS
PHYSIOLOGY
POTASSIUM COMPOUNDS
RADIOISOTOPES
RATS
RODENTS
SODIUM 22
SODIUM ISOTOPES
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES