Muscle α-aminoisobutyric acid transport after exercise

Enhanced stimulation by insulin

A. Zorzano, T. W. Balon, L. P. Garetto

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

After exercise the ability of insulin to stimulate glucose transport and glycogen synthesis in rat skeletal muscle is markedly enhanced. The present study was designed to determine whether prior exercise augments the stimulation of other processes by insulin and, if so, whether this can be attributed to an increase in insulin binding to its receptor. Toward this end rats were run on a treadmill for 45 min at moderate intensity and the uptake of α-aminoisobutyric acid (AIB) by muscle was then assessed using the isolated perfused hindquarter preparation. Approximately 30 min after the cessation of exercise, both the sensitivity and responsiveness of insulin-stimulated AIB uptake were significantly enhanced in the soleus and the red portion of the gastocnemius. As previously shown for glucose transport and glycogen synthesis, only small effects were observed in the white portion of the gastrocnemius, which unlike the other muscles was not depleted of glycogen during the run. Insulin-stimulated glucose utilization was also enhanced in the incubated soleus muscle of exercised rats; however, insulin binding to the soleus was not altered. These studies indicate that the ability of insulin to stimulate processes other than glucose transport and glycogen synthesis is enhanced in skeletal muscle after exercise and that this is not due to an alteration in insulin binding. The changes in insulin-stimulated AIB uptake and glucose metabolism after exercise are the reverse of those found in denervated and immobilized muscle and in both situations insulin binding is not altered. This suggests that a common factor(s) modulates the increase in insulin effect after exercise and the insulin resistance of disuse.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume11
Issue number5
StatePublished - 1985
Externally publishedYes

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Aminoisobutyric Acids
Muscle
Insulin
Muscles
Glycogen
Glucose
Skeletal Muscle
Rats
Insulin Resistance
Exercise equipment
Metabolism

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology
  • Physiology

Cite this

Muscle α-aminoisobutyric acid transport after exercise : Enhanced stimulation by insulin. / Zorzano, A.; Balon, T. W.; Garetto, L. P.

In: American Journal of Physiology - Endocrinology and Metabolism, Vol. 11, No. 5, 1985.

Research output: Contribution to journalArticle

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