Caffeine acutely activates 5′adenosine monophosphate–activated protein kinase and increases insulin-independent glucose transport in rat skeletal muscles

Jul 18, 2009Metabolism: clinical and experimental

Caffeine quickly activates energy regulation and boosts insulin-free sugar uptake in rat muscles

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Caffeine incubation increased the phosphorylation of AMPKalpha Thr(172) in rat skeletal muscle.

Caffeine may stimulate AMPK activation, similar to the effects of exercise.
Increased AMPK activity was observed in both AMPKalpha1 and alpha2 isoforms.
Caffeine administration resulted in a reduction of phosphocreatine content in muscles.
An increased rate of glucose transport occurred in the absence of insulin following caffeine treatment.
These findings suggest caffeine may play a role in regulating muscle metabolism.

AI simplified

Caffeine (1,3,7-trimethylxanthine) has been implicated in the regulation of glucose and lipid metabolism including actions such as insulin-independent glucose transport, glucose transporter 4 expression, and fatty acid utilization in skeletal muscle. These effects are similar to the exercise-induced and 5'adenosine monophosphate-activated protein kinase (AMPK)-mediated metabolic changes in skeletal muscle, suggesting that caffeine is involved in the regulation of muscle metabolism through AMPK activation. We explored whether caffeine acts on skeletal muscle to stimulate AMPK. Incubation of rat epitrochlearis and soleus muscles with Krebs buffer containing caffeine (> or =3 mmol/L, > or =15 minutes) increased the phosphorylation of AMPKalpha Thr(172), an essential step for full kinase activation, and acetyl-coenzyme A carboxylase Ser(79), a downstream target of AMPK, in dose- and time-dependent manners. Analysis of isoform-specific AMPK activity revealed that both AMPKalpha1 and alpha2 activities increased significantly. This enzyme activation was associated with a reduction in phosphocreatine content and an increased rate of 3-O-methyl-d-glucose transport activity in the absence of insulin. These results suggest that caffeine has similar actions to exercise by acutely stimulating skeletal muscle AMPK activity and insulin-independent glucose transport with a reduction of the intracellular energy status.

Full Text

Full text is available at the source.

View full text (XML) ↗View full text ↗

Caffeine acutely activates 5′adenosine monophosphate–activated protein kinase and increases insulin-independent glucose transport in rat skeletal muscles

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief