In vivo exercise followed by in vitro contraction additively elevates subsequent insulin-stimulated glucose transport by rat skeletal muscle

Katsuhiko Funai, George G. Schweitzer, Carlos M. Castorena, Makoto Kanzaki, Gregory D. Cartee

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

The cellular mechanisms whereby prior exercise enhances insulin-stimulated glucose transport (GT) are not well understood. Previous studies suggested that a prolonged increase in phosphorylation of Akt substrate of 160 kDa (AS160) may be important for the postexercise increase in insulin sensitivity. In the current study, the effects of in vivo exercise and in vitro contraction on subsequent insulin-stimulated GT were studied separately and together. Consistent with results from previous studies, prior exercise resulted in an increase in AS160 642Thr phosphorylation immediately after exercise in rat epitrochlearis muscles, and this increase remained 3 h postexercise concomitant with enhanced insulin-stimulated GT. For experiments with in vitro contraction, isolated rat epitrochlearis muscles were electrically stimulated to contract in the presence or absence of rat serum. As expected, insulin-stimulated GT measured 3 h after electrical stimulation in serum, but not after electrical stimulation without serum, exceeded resting controls. Immediately after electrical stimulation with or without serum, phosphorylation of both AS160 (detected by phospho-Akt substrate, PAS, antibody, or phospho-642Thr antibody) and its paralog TBC1D1 (detected by phospho-237Ser antibody) was increased. However, both AS160 and TBC1D1 phosphorylation had reversed to resting values at 3 h poststimulation with or without serum. Increasing the amount of exercise (from 1 to 2 h) or electrical stimulation (from 5 to 10 tetani) did not further elevate insulin-stimulated GT. In contrast, the combination of prior exercise and electrical stimulation had an additive effect on the subsequent increase in insulin-stimulated GT, suggesting that these exercise and electrical stimulation protocols may amplify insulin-stimulated GT through distinct mechanisms, with a persistent increase in AS160 phosphorylation potentially important for increased insulin sensitivity after exercise, but not after in vitro contraction.

Original languageEnglish (US)
Pages (from-to)E999-E1010
JournalAmerican Journal of Physiology - Endocrinology and Metabolism
Volume298
Issue number5
DOIs
StatePublished - May 1 2010
Externally publishedYes

Fingerprint

Skeletal Muscle
Electric Stimulation
Insulin
Glucose
Phosphorylation
Serum
Insulin Resistance
Antibodies
Muscles
Tetanus
In Vitro Techniques

Keywords

  • Akt substrate of 160 kDa
  • Glucose transporter 4
  • Insulin sensitivity
  • TBC1D1
  • TBC1D4

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Physiology
  • Physiology (medical)

Cite this

In vivo exercise followed by in vitro contraction additively elevates subsequent insulin-stimulated glucose transport by rat skeletal muscle. / Funai, Katsuhiko; Schweitzer, George G.; Castorena, Carlos M.; Kanzaki, Makoto; Cartee, Gregory D.

In: American Journal of Physiology - Endocrinology and Metabolism, Vol. 298, No. 5, 01.05.2010, p. E999-E1010.

Research output: Contribution to journalArticle

@article{03deda26f88d426b9988c81f10706276,
title = "In vivo exercise followed by in vitro contraction additively elevates subsequent insulin-stimulated glucose transport by rat skeletal muscle",
abstract = "The cellular mechanisms whereby prior exercise enhances insulin-stimulated glucose transport (GT) are not well understood. Previous studies suggested that a prolonged increase in phosphorylation of Akt substrate of 160 kDa (AS160) may be important for the postexercise increase in insulin sensitivity. In the current study, the effects of in vivo exercise and in vitro contraction on subsequent insulin-stimulated GT were studied separately and together. Consistent with results from previous studies, prior exercise resulted in an increase in AS160 642Thr phosphorylation immediately after exercise in rat epitrochlearis muscles, and this increase remained 3 h postexercise concomitant with enhanced insulin-stimulated GT. For experiments with in vitro contraction, isolated rat epitrochlearis muscles were electrically stimulated to contract in the presence or absence of rat serum. As expected, insulin-stimulated GT measured 3 h after electrical stimulation in serum, but not after electrical stimulation without serum, exceeded resting controls. Immediately after electrical stimulation with or without serum, phosphorylation of both AS160 (detected by phospho-Akt substrate, PAS, antibody, or phospho-642Thr antibody) and its paralog TBC1D1 (detected by phospho-237Ser antibody) was increased. However, both AS160 and TBC1D1 phosphorylation had reversed to resting values at 3 h poststimulation with or without serum. Increasing the amount of exercise (from 1 to 2 h) or electrical stimulation (from 5 to 10 tetani) did not further elevate insulin-stimulated GT. In contrast, the combination of prior exercise and electrical stimulation had an additive effect on the subsequent increase in insulin-stimulated GT, suggesting that these exercise and electrical stimulation protocols may amplify insulin-stimulated GT through distinct mechanisms, with a persistent increase in AS160 phosphorylation potentially important for increased insulin sensitivity after exercise, but not after in vitro contraction.",
keywords = "Akt substrate of 160 kDa, Glucose transporter 4, Insulin sensitivity, TBC1D1, TBC1D4",
author = "Katsuhiko Funai and Schweitzer, {George G.} and Castorena, {Carlos M.} and Makoto Kanzaki and Cartee, {Gregory D.}",
year = "2010",
month = "5",
day = "1",
doi = "10.1152/ajpendo.00758.2009",
language = "English (US)",
volume = "298",
pages = "E999--E1010",
journal = "American Journal of Physiology - Heart and Circulatory Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "5",

}

TY - JOUR

T1 - In vivo exercise followed by in vitro contraction additively elevates subsequent insulin-stimulated glucose transport by rat skeletal muscle

AU - Funai, Katsuhiko

AU - Schweitzer, George G.

AU - Castorena, Carlos M.

AU - Kanzaki, Makoto

AU - Cartee, Gregory D.

PY - 2010/5/1

Y1 - 2010/5/1

N2 - The cellular mechanisms whereby prior exercise enhances insulin-stimulated glucose transport (GT) are not well understood. Previous studies suggested that a prolonged increase in phosphorylation of Akt substrate of 160 kDa (AS160) may be important for the postexercise increase in insulin sensitivity. In the current study, the effects of in vivo exercise and in vitro contraction on subsequent insulin-stimulated GT were studied separately and together. Consistent with results from previous studies, prior exercise resulted in an increase in AS160 642Thr phosphorylation immediately after exercise in rat epitrochlearis muscles, and this increase remained 3 h postexercise concomitant with enhanced insulin-stimulated GT. For experiments with in vitro contraction, isolated rat epitrochlearis muscles were electrically stimulated to contract in the presence or absence of rat serum. As expected, insulin-stimulated GT measured 3 h after electrical stimulation in serum, but not after electrical stimulation without serum, exceeded resting controls. Immediately after electrical stimulation with or without serum, phosphorylation of both AS160 (detected by phospho-Akt substrate, PAS, antibody, or phospho-642Thr antibody) and its paralog TBC1D1 (detected by phospho-237Ser antibody) was increased. However, both AS160 and TBC1D1 phosphorylation had reversed to resting values at 3 h poststimulation with or without serum. Increasing the amount of exercise (from 1 to 2 h) or electrical stimulation (from 5 to 10 tetani) did not further elevate insulin-stimulated GT. In contrast, the combination of prior exercise and electrical stimulation had an additive effect on the subsequent increase in insulin-stimulated GT, suggesting that these exercise and electrical stimulation protocols may amplify insulin-stimulated GT through distinct mechanisms, with a persistent increase in AS160 phosphorylation potentially important for increased insulin sensitivity after exercise, but not after in vitro contraction.

AB - The cellular mechanisms whereby prior exercise enhances insulin-stimulated glucose transport (GT) are not well understood. Previous studies suggested that a prolonged increase in phosphorylation of Akt substrate of 160 kDa (AS160) may be important for the postexercise increase in insulin sensitivity. In the current study, the effects of in vivo exercise and in vitro contraction on subsequent insulin-stimulated GT were studied separately and together. Consistent with results from previous studies, prior exercise resulted in an increase in AS160 642Thr phosphorylation immediately after exercise in rat epitrochlearis muscles, and this increase remained 3 h postexercise concomitant with enhanced insulin-stimulated GT. For experiments with in vitro contraction, isolated rat epitrochlearis muscles were electrically stimulated to contract in the presence or absence of rat serum. As expected, insulin-stimulated GT measured 3 h after electrical stimulation in serum, but not after electrical stimulation without serum, exceeded resting controls. Immediately after electrical stimulation with or without serum, phosphorylation of both AS160 (detected by phospho-Akt substrate, PAS, antibody, or phospho-642Thr antibody) and its paralog TBC1D1 (detected by phospho-237Ser antibody) was increased. However, both AS160 and TBC1D1 phosphorylation had reversed to resting values at 3 h poststimulation with or without serum. Increasing the amount of exercise (from 1 to 2 h) or electrical stimulation (from 5 to 10 tetani) did not further elevate insulin-stimulated GT. In contrast, the combination of prior exercise and electrical stimulation had an additive effect on the subsequent increase in insulin-stimulated GT, suggesting that these exercise and electrical stimulation protocols may amplify insulin-stimulated GT through distinct mechanisms, with a persistent increase in AS160 phosphorylation potentially important for increased insulin sensitivity after exercise, but not after in vitro contraction.

KW - Akt substrate of 160 kDa

KW - Glucose transporter 4

KW - Insulin sensitivity

KW - TBC1D1

KW - TBC1D4

UR - http://www.scopus.com/inward/record.url?scp=77950801393&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77950801393&partnerID=8YFLogxK

U2 - 10.1152/ajpendo.00758.2009

DO - 10.1152/ajpendo.00758.2009

M3 - Article

C2 - 20179245

AN - SCOPUS:77950801393

VL - 298

SP - E999-E1010

JO - American Journal of Physiology - Heart and Circulatory Physiology

JF - American Journal of Physiology - Heart and Circulatory Physiology

SN - 0363-6135

IS - 5

ER -