|Local hindlimb antioxidant infusion does not affect muscle glucose uptake during in situ contractions in rat.|
|PMID: 20203065 Owner: NLM Status: MEDLINE|
|There is evidence that reactive oxygen species (ROS) contribute to the regulation of skeletal muscle glucose uptake during highly fatiguing ex vivo contraction conditions via AMP-activated protein kinase (AMPK). In this study we investigated the role of ROS in the regulation of glucose uptake and AMPK signaling during low-moderate intensity in situ hindlimb muscle contractions in rats, which is a more physiological protocol and preparation. Male hooded Wistar rats were anesthetized, and then N-acetylcysteine (NAC) was infused into the epigastric artery (125 mg.kg(-1).h(-1)) of one hindlimb (contracted leg) for 15 min before this leg was electrically stimulated (0.1-ms impulse at 2 Hz and 35 V) to contract at a low-moderate intensity for 15 min. The contralateral leg did not receive stimulation or local NAC infusion (rest leg). NAC infusion increased (P<0.05) plasma cysteine and cystine (by approximately 360- and 1.4-fold, respectively) and muscle cysteine (by 1.5-fold, P=0.001). Although contraction did not significantly alter muscle tyrosine nitration, reduced (GSH) or oxidized glutathione (GSSG) content, S-glutathionylation of protein bands at approximately 250 and 150 kDa was increased (P<0.05) approximately 1.7-fold by contraction, and this increase was prevented by NAC. Contraction increased (P<0.05) skeletal muscle glucose uptake 20-fold, AMPK phosphorylation 6-fold, ACCbeta phosphorylation 10-fold, and p38 MAPK phosphorylation 60-fold, and the muscle fatigued by approximately 30% during contraction and NAC infusion had no significant effect on any of these responses. This was despite NAC preventing increases in S-glutathionylation with contraction. In conclusion, unlike during highly fatiguing ex vivo contractions, local NAC infusion during in situ low-moderate intensity hindlimb contractions in rats, a more physiological preparation, does not attenuate increases in skeletal muscle glucose uptake or AMPK signaling.|
|T L Merry; R M Dywer; E A Bradley; S Rattigan; G K McConell|
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|Type: Journal Article Date: 2010-03-04|
|Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 108 ISSN: 1522-1601 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2010 May|
|Created Date: 2010-05-05 Completed Date: 2010-08-12 Revised Date: -|
Medline Journal Info:
|Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States|
|Languages: eng Pagination: 1275-83 Citation Subset: IM|
|Department of Physiology, The University of Melbourne, Parkville, Victoria 3010, Australia. email@example.com|
|APA/MLA Format Download EndNote Download BibTex|
AMP-Activated Protein Kinases
Acetylcysteine / administration & dosage*, metabolism
Antioxidants / administration & dosage*, metabolism
Cysteine / blood
Cystine / blood
Glucose / metabolism*
Glutathione / metabolism
Muscle, Skeletal / blood supply, drug effects*, innervation, metabolism
Reactive Oxygen Species / metabolism
Regional Blood Flow
Tyrosine / metabolism
p38 Mitogen-Activated Protein Kinases / metabolism
|0/Antioxidants; 0/Reactive Oxygen Species; 50-99-7/Glucose; 52-90-4/Cysteine; 55520-40-6/Tyrosine; 56-89-3/Cystine; 616-91-1/Acetylcysteine; 70-18-8/Glutathione; EC 126.96.36.199/AMP-Activated Protein Kinases; EC 188.8.131.52/p38 Mitogen-Activated Protein Kinases|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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