Glycogen metabolism during tension generation and maintenance in vascular smooth muscle

Ron Lynch, C. P. Kuettner, R. J. Paul

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

To study the regulation of glycogen utilization in vascular smooth muscle, we measured the content of glycogen and glucose 6-phosphate and the activity of the glycogen phosphorylase and glycogen debrancher enzymes in porcine carotid artery. During active contraction, the rates of glycogen phosphorylase and glycogenolysis were as high as expected. Despite this, glycogen content did not decrease to less than ~50% of control levels even after sustained contractions. The activity of glycogen debrancher enzyme was found to be limiting glycogen utilization at this point. Although glycogenolysis is closely coordinated with increases in oxidative metabolism concomitant with active contraction, the maximal level of tension obtained after stimulation was not substantially reduced under conditions where glycogen debrancher enzyme was limiting glycogen utilization. On the other hand, the rate of tension generation was increased in these tissues. Thus glycogen utilization is not necessary for maximal force generation per se, but may influence other muscle contractile properties. Finally, during steady-state tension maintenance, glycogen utilization is likely to be regulated by the intracellular concentrations of metabolic intermediates (glucose, glucose 6-phosphate), as it is in skeletal muscle.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume257
Issue number4
StatePublished - 1989
Externally publishedYes

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Glycogen
Vascular Smooth Muscle
Metabolism
Muscle
Maintenance
Glycogen Phosphorylase
Glycogenolysis
Glucose-6-Phosphate
Enzymes
Level control
Carotid Arteries
Skeletal Muscle
Swine
Tissue
Glucose
Muscles

ASJC Scopus subject areas

  • Cell Biology
  • Clinical Biochemistry
  • Physiology

Cite this

Glycogen metabolism during tension generation and maintenance in vascular smooth muscle. / Lynch, Ron; Kuettner, C. P.; Paul, R. J.

In: American Journal of Physiology - Cell Physiology, Vol. 257, No. 4, 1989.

Research output: Contribution to journalArticle

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