betik-skeletalmuscle-2016.pdf (1.07 MB)
Skeletal muscle glucose uptake during treadmill exercise in neuronal nitric oxide synthase-µ knockout mice
journal contribution
posted on 2016-05-15, 00:00 authored by Y H Hong, C Yang, Andrew BetikAndrew Betik, R S Lee-Young, G K McConellNitric oxide influences intramuscular signaling that affects skeletal muscle glucose uptake during exercise. The role of the main NO-producing enzyme isoform activated during skeletal muscle contraction, neuronal nitric oxide synthase-μ (nNOSμ), in modulating glucose uptake has not been investigated in a physiological exercise model. In this study, conscious and unrestrained chronically catheterized nNOSμ+/+ and nNOSμ−/− mice either remained at rest or ran on a treadmill at 17 m/min for 30 min. Both groups of mice demonstrated similar exercise capacity during a maximal exercise test to exhaustion (17.7 ± 0.6 vs. 15.9 ± 0.9 min for nNOSμ+/+ and nNOSμ−/−, respectively, P > 0.05). Resting and exercise blood glucose levels were comparable between the genotypes. Very low levels of NOS activity were detected in skeletal muscle from nNOSμ−/− mice, and exercise increased NOS activity only in nNOSμ+/+ mice (4.4 ± 0.3 to 5.2 ± 0.4 pmol·mg−1·min−1, P < 0.05). Exercise significantly increased glucose uptake in gastrocnemius muscle (5- to 7-fold) and, surprisingly, more so in nNOSμ−/− than in nNOSμ+/+ mice ( P < 0.05). This is in parallel with a greater increase in AMPK phosphorylation during exercise in nNOSμ−/− mice. In conclusion, nNOSμ is not essential for skeletal muscle glucose uptake during exercise, and the higher skeletal muscle glucose uptake during exercise in nNOSμ−/− mice may be due to compensatory increases in AMPK activation.
History
Journal
American Journal of Physiology - Endocrinology and MetabolismVolume
310Issue
10Pagination
E838 - E845Publisher
AMER PHYSIOLOGICAL SOCLocation
United StatesPublisher DOI
Link to full text
ISSN
0193-1849eISSN
1522-1555Language
EnglishPublication classification
C1.1 Refereed article in a scholarly journal; C Journal articleCopyright notice
2016, American Physiological SocietyUsage metrics
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No categories selectedKeywords
Science & TechnologyLife Sciences & BiomedicineEndocrinology & MetabolismPhysiologyglucose transportnitric oxideAMPKACTIVATED PROTEIN-KINASEIN-VIVOBLOOD-FLOWMETABOLIC STRESSREACTIVE OXYGENNOS INHIBITIONCONTRACTIONTRANSPORTINSULINMOUSEAMP-Activated Protein KinasesAnimalsBlood GlucoseFemaleGlucoseMaleMiceMice, KnockoutMuscle, SkeletalNitric Oxide Synthase Type IPhosphorylationPhysical Conditioning, Animal
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