What question did this study set out to answer?

To determine whether insulin stimulation and physical exercise shift the control of skeletal muscle glucose uptake from membrane transport toward glucose delivery and intracellular glucose phosphorylation.

December 1, 1998Journal of Applied Physiology

Limitations to exercise- and maximal insulin-stimulated muscle glucose uptake

View Full Paper

Ask AI

Bookmark

Authors

AHAmy E. HalsethAvidity (United States)DBDeanna P. BracyVanderbilt University DWDavid H. WassermanVanderbilt University

Discussion

Member takes

Overview

Experimental study demonstrates that glucose phosphorylation limits exercise-induced muscle glucose uptake in rats, suggesting distinct regulatory bottlenecks between exercise and insulin.

Key Points

To determine whether insulin stimulation and physical exercise shift the control of skeletal muscle glucose uptake from membrane transport toward glucose delivery and intracellular glucose phosphorylation.
Assessed conscious rats under three experimental conditions: euglycemic hyperinsulinemia (Ins; 20 mU/[kg·min]; n = 7), treadmill exercise (Ex; n = 6), and sedentary basal controls (Bas; n = 13).
Infused 3-O-[3H]methyl-D-glucose and [U-14C]mannitol to calculate the transsarcolemmal glucose gradient (TSGG), inner/outer sarcolemmal glucose concentrations ([G]im and [G]om), and infused 2-deoxy-[3H]glucose to determine the glucose metabolic index (Rg) in soleus muscle.
Soleus Rg increased significantly in the Ins group and rose further in the Ex group relative to basal controls.
Insulin decreased total soleus glucose, [G]om, and TSGG while [G]im stayed near zero; conversely, exercise increased total soleus glucose and [G]im without reducing [G]om.
Free intracellular 2-deoxy-[3H]glucose accumulated in soleus during both exercise and insulin stimulation, demonstrating that glucose phosphorylation limits uptake during exercise, whereas both delivery and phosphorylation constrain uptake under hyperinsulinemia.

Cite This Study

Halseth et al. (1998) studied this question.

synapsesocial.com/papers/6a8563e1d8017c721f4e1b66 https://doi.org/10.1152/jappl.1998.85.6.2305

View Full Paper

Ask AI

Bookmark

December 1, 1998Journal of Applied Physiology

Limitations to exercise- and maximal insulin-stimulated muscle glucose uptake

View Full Paper

Ask AI

Bookmark

Authors

AHAmy E. HalsethAvidity (United States)DBDeanna P. BracyVanderbilt University DWDavid H. WassermanVanderbilt University

Discussion

Member takes

Overview

Experimental study demonstrates that glucose phosphorylation limits exercise-induced muscle glucose uptake in rats, suggesting distinct regulatory bottlenecks between exercise and insulin.

Key Points

To determine whether insulin stimulation and physical exercise shift the control of skeletal muscle glucose uptake from membrane transport toward glucose delivery and intracellular glucose phosphorylation.
Assessed conscious rats under three experimental conditions: euglycemic hyperinsulinemia (Ins; 20 mU/[kg·min]; n = 7), treadmill exercise (Ex; n = 6), and sedentary basal controls (Bas; n = 13).
Infused 3-O-[3H]methyl-D-glucose and [U-14C]mannitol to calculate the transsarcolemmal glucose gradient (TSGG), inner/outer sarcolemmal glucose concentrations ([G]im and [G]om), and infused 2-deoxy-[3H]glucose to determine the glucose metabolic index (Rg) in soleus muscle.
Soleus Rg increased significantly in the Ins group and rose further in the Ex group relative to basal controls.
Insulin decreased total soleus glucose, [G]om, and TSGG while [G]im stayed near zero; conversely, exercise increased total soleus glucose and [G]im without reducing [G]om.
Free intracellular 2-deoxy-[3H]glucose accumulated in soleus during both exercise and insulin stimulation, demonstrating that glucose phosphorylation limits uptake during exercise, whereas both delivery and phosphorylation constrain uptake under hyperinsulinemia.

Cite This Study

Halseth et al. (1998) studied this question.

synapsesocial.com/papers/6a8563e1d8017c721f4e1b66 https://doi.org/10.1152/jappl.1998.85.6.2305

Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

View Full Paper

Ask AI

Bookmark