Substrate interconversion in dog kidney cortex slices

regulation by ECF pH

D. H. Pashley, J. J. Cohen

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The kidney utilizes far more substrate than it can oxidize. Some of the factors that regulate the metabolic fates of the excess substrate utilized by slices of dog kidney cortex were investigated. They were found to be: substrate specificity, substrate concentration, and the pH of extracellular fluid (ECF pH). Neutral substrates, glycerol or fructose, were converted largely to glucose and lactic acid and, to a smaller extent, to CO2; as substrate concentration was raised, the relative amounts of glucose or lactic acid formed were regulated by ECF pH in such a manner as to suggest a pH regulatory feedback mechanism. More of two acidic substrates, lactate and α KG, were oxidized to CO2, and their oxidation was not affected by changes in medium pH. In contrast, conversion of citrate to CO2 and glucose increased as medium pH decreased. There appear to be two types of metabolic pathways in kidney cortex: a pathway for energy production by aerobic oxidation, utilizing primarily acidic substances; and a pathway for conversion of certain substrates, which are utilizable by few tissues, to products which are taken up by most tissues. This latter pathway is regulated by ECF pH and substrate concentration and, in turn, may regulate the substrate concentrations made available to other tissues.

Original languageEnglish (US)
Pages (from-to)1519-1528
Number of pages10
JournalAmerican Journal of Physiology
Volume225
Issue number6
StatePublished - Dec 1 1973

Fingerprint

Kidney Cortex
Dogs
Lactic Acid
Glucose
Extracellular Fluid
Substrate Specificity
Metabolic Networks and Pathways
Fructose
Citric Acid
Glycerol
Kidney

ASJC Scopus subject areas

  • Physiology (medical)

Cite this

Substrate interconversion in dog kidney cortex slices : regulation by ECF pH. / Pashley, D. H.; Cohen, J. J.

In: American Journal of Physiology, Vol. 225, No. 6, 01.12.1973, p. 1519-1528.

Research output: Contribution to journalArticle

Pashley, D. H. ; Cohen, J. J. / Substrate interconversion in dog kidney cortex slices : regulation by ECF pH. In: American Journal of Physiology. 1973 ; Vol. 225, No. 6. pp. 1519-1528.
@article{10f4b5d4ee46485eab7fc146980dd427,
title = "Substrate interconversion in dog kidney cortex slices: regulation by ECF pH",
abstract = "The kidney utilizes far more substrate than it can oxidize. Some of the factors that regulate the metabolic fates of the excess substrate utilized by slices of dog kidney cortex were investigated. They were found to be: substrate specificity, substrate concentration, and the pH of extracellular fluid (ECF pH). Neutral substrates, glycerol or fructose, were converted largely to glucose and lactic acid and, to a smaller extent, to CO2; as substrate concentration was raised, the relative amounts of glucose or lactic acid formed were regulated by ECF pH in such a manner as to suggest a pH regulatory feedback mechanism. More of two acidic substrates, lactate and α KG, were oxidized to CO2, and their oxidation was not affected by changes in medium pH. In contrast, conversion of citrate to CO2 and glucose increased as medium pH decreased. There appear to be two types of metabolic pathways in kidney cortex: a pathway for energy production by aerobic oxidation, utilizing primarily acidic substances; and a pathway for conversion of certain substrates, which are utilizable by few tissues, to products which are taken up by most tissues. This latter pathway is regulated by ECF pH and substrate concentration and, in turn, may regulate the substrate concentrations made available to other tissues.",
author = "Pashley, {D. H.} and Cohen, {J. J.}",
year = "1973",
month = "12",
day = "1",
language = "English (US)",
volume = "225",
pages = "1519--1528",
journal = "American Journal of Physiology - Heart and Circulatory Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "6",

}

TY - JOUR

T1 - Substrate interconversion in dog kidney cortex slices

T2 - regulation by ECF pH

AU - Pashley, D. H.

AU - Cohen, J. J.

PY - 1973/12/1

Y1 - 1973/12/1

N2 - The kidney utilizes far more substrate than it can oxidize. Some of the factors that regulate the metabolic fates of the excess substrate utilized by slices of dog kidney cortex were investigated. They were found to be: substrate specificity, substrate concentration, and the pH of extracellular fluid (ECF pH). Neutral substrates, glycerol or fructose, were converted largely to glucose and lactic acid and, to a smaller extent, to CO2; as substrate concentration was raised, the relative amounts of glucose or lactic acid formed were regulated by ECF pH in such a manner as to suggest a pH regulatory feedback mechanism. More of two acidic substrates, lactate and α KG, were oxidized to CO2, and their oxidation was not affected by changes in medium pH. In contrast, conversion of citrate to CO2 and glucose increased as medium pH decreased. There appear to be two types of metabolic pathways in kidney cortex: a pathway for energy production by aerobic oxidation, utilizing primarily acidic substances; and a pathway for conversion of certain substrates, which are utilizable by few tissues, to products which are taken up by most tissues. This latter pathway is regulated by ECF pH and substrate concentration and, in turn, may regulate the substrate concentrations made available to other tissues.

AB - The kidney utilizes far more substrate than it can oxidize. Some of the factors that regulate the metabolic fates of the excess substrate utilized by slices of dog kidney cortex were investigated. They were found to be: substrate specificity, substrate concentration, and the pH of extracellular fluid (ECF pH). Neutral substrates, glycerol or fructose, were converted largely to glucose and lactic acid and, to a smaller extent, to CO2; as substrate concentration was raised, the relative amounts of glucose or lactic acid formed were regulated by ECF pH in such a manner as to suggest a pH regulatory feedback mechanism. More of two acidic substrates, lactate and α KG, were oxidized to CO2, and their oxidation was not affected by changes in medium pH. In contrast, conversion of citrate to CO2 and glucose increased as medium pH decreased. There appear to be two types of metabolic pathways in kidney cortex: a pathway for energy production by aerobic oxidation, utilizing primarily acidic substances; and a pathway for conversion of certain substrates, which are utilizable by few tissues, to products which are taken up by most tissues. This latter pathway is regulated by ECF pH and substrate concentration and, in turn, may regulate the substrate concentrations made available to other tissues.

UR - http://www.scopus.com/inward/record.url?scp=0015752232&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0015752232&partnerID=8YFLogxK

M3 - Article

VL - 225

SP - 1519

EP - 1528

JO - American Journal of Physiology - Heart and Circulatory Physiology

JF - American Journal of Physiology - Heart and Circulatory Physiology

SN - 0363-6135

IS - 6

ER -