Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney

Research output: Chapter in Book/Report/Conference proceedingChapter

79 Citations (Scopus)

Abstract

In vitro microperfusion experiments were performed to investigate the mechanism of bicarbonate absorption in the cortical thick ascending limb of the rat. Tubules were perfused at 1.0-1.5 nl·min-1·mm-1 and bicarbonate concentration was 25 mM in the perfusate and bath. Bicarbonate absorption rates were determined by microcalorimetry. Control tubules absorbed bicarbonate at a mean rate of 9.5 ± 0.6 pmol·min-1·mm-1. The limiting luminal bicarbonate concentration was approximately 5 mM for tubules perfused at slow rates with 25 mM bicarbonate in the bath. Acetazolamide (10-4 M) in the bath reduced bicarbonate absorption by 76% without significant effect on transepithelial voltage. Removing sodium from the perfusate and bath or removing potassium from the bath reduced bicarbonate absorption and transepithelial voltage to near zero. Adding amiloride (5 x 10-4 or 10-3 M) to the perfusate reduced bicarbonate absorption by 60-75% without detectable effect on transepithelial voltage. Adding furosemide (10-4 M) to the perfusate increased bicarbonate absorption significantly by 40-50% while decreasing transepithelial voltage from 17 to 1.8 mV. Thus, bicarbonate absorption by cortical thick ascending limbs requires carbonic anhydrase activity and sodium transport but is not dependent on transepithelial voltage. When considered together, the results are consistent with mediation of the bicarbonate absorption by apical membrane sodium-hydrogen exchange.

Original languageEnglish (US)
Title of host publicationAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume17
Edition6
StatePublished - 1985
Externally publishedYes

Fingerprint

Sodium Bicarbonate
Bicarbonates
Extremities
Kidney
Baths
Sodium
Acetazolamide
Carbonic Anhydrases
Amiloride
Furosemide
Hydrogen
Potassium

ASJC Scopus subject areas

  • Medicine(all)

Cite this

Good, D. (1985). Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney. In American Journal of Physiology - Renal Fluid and Electrolyte Physiology (6 ed., Vol. 17)

Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney. / Good, David.

American Journal of Physiology - Renal Fluid and Electrolyte Physiology. Vol. 17 6. ed. 1985.

Research output: Chapter in Book/Report/Conference proceedingChapter

Good, D 1985, Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney. in American Journal of Physiology - Renal Fluid and Electrolyte Physiology. 6 edn, vol. 17.
Good D. Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney. In American Journal of Physiology - Renal Fluid and Electrolyte Physiology. 6 ed. Vol. 17. 1985
Good, David. / Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney. American Journal of Physiology - Renal Fluid and Electrolyte Physiology. Vol. 17 6. ed. 1985.
@inbook{6c90968951ca4108931cafa6774ae0ad,
title = "Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney",
abstract = "In vitro microperfusion experiments were performed to investigate the mechanism of bicarbonate absorption in the cortical thick ascending limb of the rat. Tubules were perfused at 1.0-1.5 nl·min-1·mm-1 and bicarbonate concentration was 25 mM in the perfusate and bath. Bicarbonate absorption rates were determined by microcalorimetry. Control tubules absorbed bicarbonate at a mean rate of 9.5 ± 0.6 pmol·min-1·mm-1. The limiting luminal bicarbonate concentration was approximately 5 mM for tubules perfused at slow rates with 25 mM bicarbonate in the bath. Acetazolamide (10-4 M) in the bath reduced bicarbonate absorption by 76{\%} without significant effect on transepithelial voltage. Removing sodium from the perfusate and bath or removing potassium from the bath reduced bicarbonate absorption and transepithelial voltage to near zero. Adding amiloride (5 x 10-4 or 10-3 M) to the perfusate reduced bicarbonate absorption by 60-75{\%} without detectable effect on transepithelial voltage. Adding furosemide (10-4 M) to the perfusate increased bicarbonate absorption significantly by 40-50{\%} while decreasing transepithelial voltage from 17 to 1.8 mV. Thus, bicarbonate absorption by cortical thick ascending limbs requires carbonic anhydrase activity and sodium transport but is not dependent on transepithelial voltage. When considered together, the results are consistent with mediation of the bicarbonate absorption by apical membrane sodium-hydrogen exchange.",
author = "David Good",
year = "1985",
language = "English (US)",
volume = "17",
booktitle = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
edition = "6",

}

TY - CHAP

T1 - Sodium-dependent bicarbonate absorption by cortical thick ascending limb of rat kidney

AU - Good, David

PY - 1985

Y1 - 1985

N2 - In vitro microperfusion experiments were performed to investigate the mechanism of bicarbonate absorption in the cortical thick ascending limb of the rat. Tubules were perfused at 1.0-1.5 nl·min-1·mm-1 and bicarbonate concentration was 25 mM in the perfusate and bath. Bicarbonate absorption rates were determined by microcalorimetry. Control tubules absorbed bicarbonate at a mean rate of 9.5 ± 0.6 pmol·min-1·mm-1. The limiting luminal bicarbonate concentration was approximately 5 mM for tubules perfused at slow rates with 25 mM bicarbonate in the bath. Acetazolamide (10-4 M) in the bath reduced bicarbonate absorption by 76% without significant effect on transepithelial voltage. Removing sodium from the perfusate and bath or removing potassium from the bath reduced bicarbonate absorption and transepithelial voltage to near zero. Adding amiloride (5 x 10-4 or 10-3 M) to the perfusate reduced bicarbonate absorption by 60-75% without detectable effect on transepithelial voltage. Adding furosemide (10-4 M) to the perfusate increased bicarbonate absorption significantly by 40-50% while decreasing transepithelial voltage from 17 to 1.8 mV. Thus, bicarbonate absorption by cortical thick ascending limbs requires carbonic anhydrase activity and sodium transport but is not dependent on transepithelial voltage. When considered together, the results are consistent with mediation of the bicarbonate absorption by apical membrane sodium-hydrogen exchange.

AB - In vitro microperfusion experiments were performed to investigate the mechanism of bicarbonate absorption in the cortical thick ascending limb of the rat. Tubules were perfused at 1.0-1.5 nl·min-1·mm-1 and bicarbonate concentration was 25 mM in the perfusate and bath. Bicarbonate absorption rates were determined by microcalorimetry. Control tubules absorbed bicarbonate at a mean rate of 9.5 ± 0.6 pmol·min-1·mm-1. The limiting luminal bicarbonate concentration was approximately 5 mM for tubules perfused at slow rates with 25 mM bicarbonate in the bath. Acetazolamide (10-4 M) in the bath reduced bicarbonate absorption by 76% without significant effect on transepithelial voltage. Removing sodium from the perfusate and bath or removing potassium from the bath reduced bicarbonate absorption and transepithelial voltage to near zero. Adding amiloride (5 x 10-4 or 10-3 M) to the perfusate reduced bicarbonate absorption by 60-75% without detectable effect on transepithelial voltage. Adding furosemide (10-4 M) to the perfusate increased bicarbonate absorption significantly by 40-50% while decreasing transepithelial voltage from 17 to 1.8 mV. Thus, bicarbonate absorption by cortical thick ascending limbs requires carbonic anhydrase activity and sodium transport but is not dependent on transepithelial voltage. When considered together, the results are consistent with mediation of the bicarbonate absorption by apical membrane sodium-hydrogen exchange.

UR - http://www.scopus.com/inward/record.url?scp=0022404846&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022404846&partnerID=8YFLogxK

M3 - Chapter

C2 - 2988349

AN - SCOPUS:0022404846

VL - 17

BT - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

ER -