title: Elevation of muscle temperature stimulates muscle glucose uptake in vivo and in vitro.
abstract: The purpose of this study was to examine whether elevation of muscle temperature per se might be a stimulatory factor to increase muscle glucose uptake. Heat stimulation to rat hindlimbs increased glucose uptake measured in vivo in the extensor digitorum longus (EDL) and soleus muscles with a significant increase in muscle temperature. This thermal effect was observed again when glucose uptake was measured in vitro in both isolated muscles immediately after the heat stimulation in vivo. When heat stimulation was imposed on isolated EDL muscles, glucose uptake was facilitated in proportion to the increase in muscle temperature. The heat stimulation led to a significant amplification in the phosphorylation of AMP-activated protein kinase (AMPK) and Akt, and treatment with compound C, wortmannin, or LY294002 partially blocked the thermal effect on muscle glucose uptake. We provide evidence that elevation of muscle temperature per se can directly stimulate muscle glucose uptake and that this thermal effect is compound C-, wortmannin-, and LY294002-inhibitable.
authors.affiliation: Department of Health and Nutrition, Niigata University of Health and Welfare, Niigata, Japan, kosinaka@nuhw.ac.jp.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Koshinaka
authors.forename: Emi
authors.initials: E
authors.lastname: Kawamoto
authors.forename: Natsuki
authors.initials: N
authors.lastname: Abe
authors.forename: Koji
authors.initials: K
authors.lastname: Toshinai
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Nakazato
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kawanaka
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport; D002867:Chromones / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006614:Hindlimb; D006358:Hot Temperature; D066298:In Vitro Techniques; D008297:Male; D009025:Morpholines / Q000494:pharmacology; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011720:Pyrazoles / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D002867:Chromones; D009025:Morpholines; D011720:Pyrazoles; D011743:Pyrimidines; C516138:dorsomorphin; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D051057:Proto-Oncogene Proteins c-akt; D055372:AMP-Activated Protein Kinases; D005947:Glucose; D000077191:Wortmannin