Lack of potassium effect on Na-Cl cotransport in the medullary thick ascending limb
The effect of potassium on sodium chloride uptake into rabbit renal medullary thick ascending limb of Henle's loop (mTALH) cells was studied to assess whether K participates in the Na-Cl cotransport system. Na uptake into the mTALH cells was inhibited 70% at 3 min by 1 mM furosemide. The total and furosemide-sensitive Na uptake was stimulated by Cl. Additionally, Cl uptake into the mTALH cells was stimulated by Na gradients and inhibited 42% at 3 min by 1 mM furosemide. Na uptake was studied in the presence of 0,5, or 140 mM external K gradients. Na uptake was similar in the absence and presence of K. Additionally, furosemide inhibited Na uptake as effectively in the absence or presence of K. Similar studies were conducted to study the effects of Na on /sup 86/Rb uptake. Na did not stimulate /sup 86/Rb uptake. The uptake of /sup 86/Rb was similar in the presence of 0,5, or 140 mM Na gradients. Furosemide had no significant inhibitory effect on /sup 86/Rb uptake. Barium (5 mM), an inhibitor of K conductance pathways, inhibited total /sup 86/Rb uptake by 19%. In the presence of 5 mM BaCl/sub 2/, Na still did not have a stimulatory effect on /sup 86/Rb uptake. The results confirm the existence of a Na-Cl cotransport system in mTALH cells, but a direct effect of K on the NaCl cotransport system could not be demonstrated under the experimental conditions used.
- Research Organization:
- Veteran's Administration Medical Center, San Francisco, CA
- OSTI ID:
- 5221209
- Journal Information:
- Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States)
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BARIUM
BIOLOGICAL EFFECTS
BENZOIC ACID
CHLORIDES
MEMBRANE TRANSPORT
UPTAKE
POTASSIUM
RUBIDIUM 86
SODIUM
BARIUM CHLORIDES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL PATHWAYS
KIDNEYS
RABBITS
SODIUM CHLORIDES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
ANIMALS
BARIUM COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KINETICS
MAMMALS
METALS
MINUTES LIVING RADIOISOTOPES
MONOCARBOXYLIC ACIDS
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
REACTION KINETICS
RUBIDIUM ISOTOPES
SODIUM COMPOUNDS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques
560172 - Radiation Effects- Nuclide Kinetics & Toxicology- Animals- (-1987)