Effect of isoproterenol on amino acid levels and protein turnover in skeletal muscle

J. B. Li, Leonard "Jim" Jefferson

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

The effect of isoproterenol on amino acid concentrations in perfusate and skeletal muscle was studied during a 3 h perfusion of the isolated rat hemicorpus. The β adrenergic agonist inhibited the accumulation of alanine, threonine, phenylalanine, tyrosine, lysine, arginine, leucine, and valine and increased the loss of glutamate, aspartate, serine, and isoleucine from the pool of free amino acids in perfusate and muscle. The loss of glutamate was accompanied by a greater accumulation of glutamine. Changes in alanine levels showed the greatest response with a net accumulation of 98 μmol in the controls becoming a net loss of 54 μmol in the experimentals. These changes in amino acid levels were accounted for in part by a 20% decrease in protein degradation. Protein synthesis was not affected by isoproterenol. In addition to an effect on degradation, it appeared that isoproterenol affected amino acid levels by increasing alanine utilization and causing formation of glutamine instead of alanine. Other effects of the drug included increased rates of lactate production, muscle glycogen breakdown, and oxygen consumption, whereas no effects were observed on ATP and creatine phosphate levels. Pyruvate content of muscle was maintained at a higher level in the presence of the drug than in control perfusions.

Original languageEnglish (US)
JournalAmerican Journal of Physiology
Volume232
Issue number2
StatePublished - Jan 1 1977

Fingerprint

Isoproterenol
Alanine
Skeletal Muscle
Amino Acids
Glutamine
Muscles
Glutamic Acid
Proteins
Perfusion
Adrenergic Agonists
Phosphocreatine
Isoleucine
Drug and Narcotic Control
Valine
Threonine
Pyruvic Acid
Phenylalanine
Glycogen
Aspartic Acid
Oxygen Consumption

All Science Journal Classification (ASJC) codes

  • Physiology (medical)

Cite this

@article{15404d3029f64c42906b9d0b74732968,
title = "Effect of isoproterenol on amino acid levels and protein turnover in skeletal muscle",
abstract = "The effect of isoproterenol on amino acid concentrations in perfusate and skeletal muscle was studied during a 3 h perfusion of the isolated rat hemicorpus. The β adrenergic agonist inhibited the accumulation of alanine, threonine, phenylalanine, tyrosine, lysine, arginine, leucine, and valine and increased the loss of glutamate, aspartate, serine, and isoleucine from the pool of free amino acids in perfusate and muscle. The loss of glutamate was accompanied by a greater accumulation of glutamine. Changes in alanine levels showed the greatest response with a net accumulation of 98 μmol in the controls becoming a net loss of 54 μmol in the experimentals. These changes in amino acid levels were accounted for in part by a 20{\%} decrease in protein degradation. Protein synthesis was not affected by isoproterenol. In addition to an effect on degradation, it appeared that isoproterenol affected amino acid levels by increasing alanine utilization and causing formation of glutamine instead of alanine. Other effects of the drug included increased rates of lactate production, muscle glycogen breakdown, and oxygen consumption, whereas no effects were observed on ATP and creatine phosphate levels. Pyruvate content of muscle was maintained at a higher level in the presence of the drug than in control perfusions.",
author = "Li, {J. B.} and Jefferson, {Leonard {"}Jim{"}}",
year = "1977",
month = "1",
day = "1",
language = "English (US)",
volume = "232",
journal = "American Journal of Physiology",
issn = "0002-9513",
publisher = "American Physiological Society",
number = "2",

}

Effect of isoproterenol on amino acid levels and protein turnover in skeletal muscle. / Li, J. B.; Jefferson, Leonard "Jim".

In: American Journal of Physiology, Vol. 232, No. 2, 01.01.1977.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of isoproterenol on amino acid levels and protein turnover in skeletal muscle

AU - Li, J. B.

AU - Jefferson, Leonard "Jim"

PY - 1977/1/1

Y1 - 1977/1/1

N2 - The effect of isoproterenol on amino acid concentrations in perfusate and skeletal muscle was studied during a 3 h perfusion of the isolated rat hemicorpus. The β adrenergic agonist inhibited the accumulation of alanine, threonine, phenylalanine, tyrosine, lysine, arginine, leucine, and valine and increased the loss of glutamate, aspartate, serine, and isoleucine from the pool of free amino acids in perfusate and muscle. The loss of glutamate was accompanied by a greater accumulation of glutamine. Changes in alanine levels showed the greatest response with a net accumulation of 98 μmol in the controls becoming a net loss of 54 μmol in the experimentals. These changes in amino acid levels were accounted for in part by a 20% decrease in protein degradation. Protein synthesis was not affected by isoproterenol. In addition to an effect on degradation, it appeared that isoproterenol affected amino acid levels by increasing alanine utilization and causing formation of glutamine instead of alanine. Other effects of the drug included increased rates of lactate production, muscle glycogen breakdown, and oxygen consumption, whereas no effects were observed on ATP and creatine phosphate levels. Pyruvate content of muscle was maintained at a higher level in the presence of the drug than in control perfusions.

AB - The effect of isoproterenol on amino acid concentrations in perfusate and skeletal muscle was studied during a 3 h perfusion of the isolated rat hemicorpus. The β adrenergic agonist inhibited the accumulation of alanine, threonine, phenylalanine, tyrosine, lysine, arginine, leucine, and valine and increased the loss of glutamate, aspartate, serine, and isoleucine from the pool of free amino acids in perfusate and muscle. The loss of glutamate was accompanied by a greater accumulation of glutamine. Changes in alanine levels showed the greatest response with a net accumulation of 98 μmol in the controls becoming a net loss of 54 μmol in the experimentals. These changes in amino acid levels were accounted for in part by a 20% decrease in protein degradation. Protein synthesis was not affected by isoproterenol. In addition to an effect on degradation, it appeared that isoproterenol affected amino acid levels by increasing alanine utilization and causing formation of glutamine instead of alanine. Other effects of the drug included increased rates of lactate production, muscle glycogen breakdown, and oxygen consumption, whereas no effects were observed on ATP and creatine phosphate levels. Pyruvate content of muscle was maintained at a higher level in the presence of the drug than in control perfusions.

UR - http://www.scopus.com/inward/record.url?scp=0017343842&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0017343842&partnerID=8YFLogxK

M3 - Article

VL - 232

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0002-9513

IS - 2

ER -