Effects of potassium on ammonia transport by medullary thick ascending limb of the rat

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Renal ammonium excretion is increased by potassium depletion and reduced by potassium loading. To determine whether changes in potassium concentration would alter ammonia transport in the medullary thick ascending limb (MAL), tubules from rats were perfused in vitro and effects of changes in K concentration within the physiological range (4-24 mM) were evaluated. Increasing K concentration from 4 to 24 mM in perfusate and bath inhibited total ammonia absorption by 50% and reduced the steady-state transepithelial NH4 + concentration gradient. The inhibition of total ammonia absorption was reversible and occurred when K replaced either Na or N-methyl-D-glucamine. Increasing K concentration in the luminal perfusate alone gave similar inhibition of total ammonia absorption. At 1-2 nl/min per mm perfusion rate, increasing K concentration in perfusion and bathing solutions had no significant effect on transepithelial voltage. With either 4 or 24 mM K in perfusate and bath, an increase in luminal perfusion rate markedly increased total ammonia absorption. Thus, both potassium concentration and luminal flow rate are important factors capable of regulating total ammonia transport by the MAL. Changes in systemic potassium balance may influence renal ammonium excretion by affecting NH4 + absorption in the MAL and altering the transfer of ammonia from loops of Henle to medullary collecting ducts.

Original languageEnglish (US)
Pages (from-to)1358-1365
Number of pages8
JournalJournal of Clinical Investigation
Volume80
Issue number5
StatePublished - 1987

Fingerprint

Ammonia
Potassium
Extremities
Perfusion
Baths
Ammonium Compounds
Loop of Henle

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Effects of potassium on ammonia transport by medullary thick ascending limb of the rat. / Good, David.

In: Journal of Clinical Investigation, Vol. 80, No. 5, 1987, p. 1358-1365.

Research output: Contribution to journalArticle

@article{c1bf3ab7fab549a58966254cd08b91ee,
title = "Effects of potassium on ammonia transport by medullary thick ascending limb of the rat",
abstract = "Renal ammonium excretion is increased by potassium depletion and reduced by potassium loading. To determine whether changes in potassium concentration would alter ammonia transport in the medullary thick ascending limb (MAL), tubules from rats were perfused in vitro and effects of changes in K concentration within the physiological range (4-24 mM) were evaluated. Increasing K concentration from 4 to 24 mM in perfusate and bath inhibited total ammonia absorption by 50{\%} and reduced the steady-state transepithelial NH4 + concentration gradient. The inhibition of total ammonia absorption was reversible and occurred when K replaced either Na or N-methyl-D-glucamine. Increasing K concentration in the luminal perfusate alone gave similar inhibition of total ammonia absorption. At 1-2 nl/min per mm perfusion rate, increasing K concentration in perfusion and bathing solutions had no significant effect on transepithelial voltage. With either 4 or 24 mM K in perfusate and bath, an increase in luminal perfusion rate markedly increased total ammonia absorption. Thus, both potassium concentration and luminal flow rate are important factors capable of regulating total ammonia transport by the MAL. Changes in systemic potassium balance may influence renal ammonium excretion by affecting NH4 + absorption in the MAL and altering the transfer of ammonia from loops of Henle to medullary collecting ducts.",
author = "David Good",
year = "1987",
language = "English (US)",
volume = "80",
pages = "1358--1365",
journal = "Journal of Clinical Investigation",
issn = "0021-9738",
publisher = "The American Society for Clinical Investigation",
number = "5",

}

TY - JOUR

T1 - Effects of potassium on ammonia transport by medullary thick ascending limb of the rat

AU - Good, David

PY - 1987

Y1 - 1987

N2 - Renal ammonium excretion is increased by potassium depletion and reduced by potassium loading. To determine whether changes in potassium concentration would alter ammonia transport in the medullary thick ascending limb (MAL), tubules from rats were perfused in vitro and effects of changes in K concentration within the physiological range (4-24 mM) were evaluated. Increasing K concentration from 4 to 24 mM in perfusate and bath inhibited total ammonia absorption by 50% and reduced the steady-state transepithelial NH4 + concentration gradient. The inhibition of total ammonia absorption was reversible and occurred when K replaced either Na or N-methyl-D-glucamine. Increasing K concentration in the luminal perfusate alone gave similar inhibition of total ammonia absorption. At 1-2 nl/min per mm perfusion rate, increasing K concentration in perfusion and bathing solutions had no significant effect on transepithelial voltage. With either 4 or 24 mM K in perfusate and bath, an increase in luminal perfusion rate markedly increased total ammonia absorption. Thus, both potassium concentration and luminal flow rate are important factors capable of regulating total ammonia transport by the MAL. Changes in systemic potassium balance may influence renal ammonium excretion by affecting NH4 + absorption in the MAL and altering the transfer of ammonia from loops of Henle to medullary collecting ducts.

AB - Renal ammonium excretion is increased by potassium depletion and reduced by potassium loading. To determine whether changes in potassium concentration would alter ammonia transport in the medullary thick ascending limb (MAL), tubules from rats were perfused in vitro and effects of changes in K concentration within the physiological range (4-24 mM) were evaluated. Increasing K concentration from 4 to 24 mM in perfusate and bath inhibited total ammonia absorption by 50% and reduced the steady-state transepithelial NH4 + concentration gradient. The inhibition of total ammonia absorption was reversible and occurred when K replaced either Na or N-methyl-D-glucamine. Increasing K concentration in the luminal perfusate alone gave similar inhibition of total ammonia absorption. At 1-2 nl/min per mm perfusion rate, increasing K concentration in perfusion and bathing solutions had no significant effect on transepithelial voltage. With either 4 or 24 mM K in perfusate and bath, an increase in luminal perfusion rate markedly increased total ammonia absorption. Thus, both potassium concentration and luminal flow rate are important factors capable of regulating total ammonia transport by the MAL. Changes in systemic potassium balance may influence renal ammonium excretion by affecting NH4 + absorption in the MAL and altering the transfer of ammonia from loops of Henle to medullary collecting ducts.

UR - http://www.scopus.com/inward/record.url?scp=0023550292&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023550292&partnerID=8YFLogxK

M3 - Article

VL - 80

SP - 1358

EP - 1365

JO - Journal of Clinical Investigation

JF - Journal of Clinical Investigation

SN - 0021-9738

IS - 5

ER -