The regulation of pyruvate dehydrogenase in brain in vivo

Richard S Jope, J. P. Blass

Research output: Contribution to journalArticle

52 Citations (Scopus)

Abstract

The activity of pyruvate dehydrogenase in the brains of mice frozen in liquid nitrogen was 14.0 nmol/min per mg protein. It rose to 23.8 nmol/min per mg protein after incubation of the brain homogenate with 10mM MgCl2 to activate (dephosphorylate) the enzyme, indicating that approx 60% of the enzyme was originally in the active form. Treatment with amobarbital or pentobarbital halved the proportion of pyruvate dehydrogenase in the active form. The proportion of pyruvate dehydrogenase in the active form increased during ischemia, activation being complete within one min. Anesthesia with amobarbital slowed the activation during ischemia but did not alter the total amount of pyruvate dehydrogenase activity. The concentration of ATP, the ATP/ADP ratio and the adenylate energy charge increased as the proportion of pyruvate dehydrogenase in the active form decreased during barbiturate anesthesia, and they decreased as the proportion of pyruvate dehydrogenase in the active form increased during ischemia. After treatment with insulin, the proportion of pyruvate dehydrogenase in the active form increased by 30% but the energy charge did not change. Treatment of mice with ether, morphine, ethanol, or diazepam did not change the proportion of pyruvate dehydrogenase in the active form although these treatments have been reported to alter pyruvate oxidation in brain in vivo. Treatments which altered pyruvate oxidation in the brain did not consistently alter the proportion of pyruvate dehydrogenase in the active form, unless they also altered energy charge.

Original languageEnglish
Pages (from-to)709-714
Number of pages6
JournalJournal of Neurochemistry
Volume26
Issue number4
StatePublished - Dec 1 1976
Externally publishedYes

Fingerprint

Pyruvic Acid
Brain
Oxidoreductases
Amobarbital
Ischemia
Anesthesia
Adenosine Triphosphate
Chemical activation
Oxidation
Magnesium Chloride
Pentobarbital
Liquid nitrogen
Enzymes
Diazepam
Ether
Adenosine Diphosphate
Morphine
Proteins
Ethanol
Nitrogen

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Cite this

The regulation of pyruvate dehydrogenase in brain in vivo. / Jope, Richard S; Blass, J. P.

In: Journal of Neurochemistry, Vol. 26, No. 4, 01.12.1976, p. 709-714.

Research output: Contribution to journalArticle

@article{b6a792299a0641acb417880cb7c2f5b1,
title = "The regulation of pyruvate dehydrogenase in brain in vivo",
abstract = "The activity of pyruvate dehydrogenase in the brains of mice frozen in liquid nitrogen was 14.0 nmol/min per mg protein. It rose to 23.8 nmol/min per mg protein after incubation of the brain homogenate with 10mM MgCl2 to activate (dephosphorylate) the enzyme, indicating that approx 60{\%} of the enzyme was originally in the active form. Treatment with amobarbital or pentobarbital halved the proportion of pyruvate dehydrogenase in the active form. The proportion of pyruvate dehydrogenase in the active form increased during ischemia, activation being complete within one min. Anesthesia with amobarbital slowed the activation during ischemia but did not alter the total amount of pyruvate dehydrogenase activity. The concentration of ATP, the ATP/ADP ratio and the adenylate energy charge increased as the proportion of pyruvate dehydrogenase in the active form decreased during barbiturate anesthesia, and they decreased as the proportion of pyruvate dehydrogenase in the active form increased during ischemia. After treatment with insulin, the proportion of pyruvate dehydrogenase in the active form increased by 30{\%} but the energy charge did not change. Treatment of mice with ether, morphine, ethanol, or diazepam did not change the proportion of pyruvate dehydrogenase in the active form although these treatments have been reported to alter pyruvate oxidation in brain in vivo. Treatments which altered pyruvate oxidation in the brain did not consistently alter the proportion of pyruvate dehydrogenase in the active form, unless they also altered energy charge.",
author = "Jope, {Richard S} and Blass, {J. P.}",
year = "1976",
month = "12",
day = "1",
language = "English",
volume = "26",
pages = "709--714",
journal = "Journal of Neurochemistry",
issn = "0022-3042",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - The regulation of pyruvate dehydrogenase in brain in vivo

AU - Jope, Richard S

AU - Blass, J. P.

PY - 1976/12/1

Y1 - 1976/12/1

N2 - The activity of pyruvate dehydrogenase in the brains of mice frozen in liquid nitrogen was 14.0 nmol/min per mg protein. It rose to 23.8 nmol/min per mg protein after incubation of the brain homogenate with 10mM MgCl2 to activate (dephosphorylate) the enzyme, indicating that approx 60% of the enzyme was originally in the active form. Treatment with amobarbital or pentobarbital halved the proportion of pyruvate dehydrogenase in the active form. The proportion of pyruvate dehydrogenase in the active form increased during ischemia, activation being complete within one min. Anesthesia with amobarbital slowed the activation during ischemia but did not alter the total amount of pyruvate dehydrogenase activity. The concentration of ATP, the ATP/ADP ratio and the adenylate energy charge increased as the proportion of pyruvate dehydrogenase in the active form decreased during barbiturate anesthesia, and they decreased as the proportion of pyruvate dehydrogenase in the active form increased during ischemia. After treatment with insulin, the proportion of pyruvate dehydrogenase in the active form increased by 30% but the energy charge did not change. Treatment of mice with ether, morphine, ethanol, or diazepam did not change the proportion of pyruvate dehydrogenase in the active form although these treatments have been reported to alter pyruvate oxidation in brain in vivo. Treatments which altered pyruvate oxidation in the brain did not consistently alter the proportion of pyruvate dehydrogenase in the active form, unless they also altered energy charge.

AB - The activity of pyruvate dehydrogenase in the brains of mice frozen in liquid nitrogen was 14.0 nmol/min per mg protein. It rose to 23.8 nmol/min per mg protein after incubation of the brain homogenate with 10mM MgCl2 to activate (dephosphorylate) the enzyme, indicating that approx 60% of the enzyme was originally in the active form. Treatment with amobarbital or pentobarbital halved the proportion of pyruvate dehydrogenase in the active form. The proportion of pyruvate dehydrogenase in the active form increased during ischemia, activation being complete within one min. Anesthesia with amobarbital slowed the activation during ischemia but did not alter the total amount of pyruvate dehydrogenase activity. The concentration of ATP, the ATP/ADP ratio and the adenylate energy charge increased as the proportion of pyruvate dehydrogenase in the active form decreased during barbiturate anesthesia, and they decreased as the proportion of pyruvate dehydrogenase in the active form increased during ischemia. After treatment with insulin, the proportion of pyruvate dehydrogenase in the active form increased by 30% but the energy charge did not change. Treatment of mice with ether, morphine, ethanol, or diazepam did not change the proportion of pyruvate dehydrogenase in the active form although these treatments have been reported to alter pyruvate oxidation in brain in vivo. Treatments which altered pyruvate oxidation in the brain did not consistently alter the proportion of pyruvate dehydrogenase in the active form, unless they also altered energy charge.

UR - http://www.scopus.com/inward/record.url?scp=0017229988&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0017229988&partnerID=8YFLogxK

M3 - Article

C2 - 965963

AN - SCOPUS:0017229988

VL - 26

SP - 709

EP - 714

JO - Journal of Neurochemistry

JF - Journal of Neurochemistry

SN - 0022-3042

IS - 4

ER -