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A Single Bout of Exercise Increases the Expression of Glucose but not Fatty Acid Transporters in Skeletal Muscle of IL‐6 KO Mice
Author(s) -
Łukaszuk B.,
Bialuk I.,
Górski J.,
Zajączkiewicz M.,
Winnicka M. M.,
Chabowski A.
Publication year - 2012
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-012-3678-x
Subject(s) - cd36 , medicine , endocrinology , skeletal muscle , glycogen , glucose transporter , fatty acid , lipid metabolism , biology , carbohydrate metabolism , chemistry , biochemistry , receptor , insulin
IL‐6 is a biologically active cytokine released during exercise by contracting skeletal muscles. It appears to be highly involved in the regulation of muscles energy substrate utilization. Whether an ablation of IL‐6 (IL‐6 KO) in mice subjected to a single bout of exercise affects lipid and/or glucose metabolism is currently unknown. In the present study we examined fatty acid (FAT/CD36, FABPpm, FATP‐1, FATP‐4) as well as glucose (GLUT‐1, GLUT‐4) transporters expression in IL‐6 KO mice. In addition, intramuscular glycogen and lipid content was also evaluated. The expression of all fatty acid transporters (FAT/CD36: +25 %; FATP‐1: +31 %; FABPpm: +12.7 %; FATP‐4: +7.2 %) was increased in muscles from IL‐6 KO mice compared to wild type (WT) mice. Accordingly intramuscular lipid content was also increased in these muscles (FFA: +38 %; DAG: +36 % and TAG: +160 %). Interestingly, IL‐6 deficiency had only minor effect on glucose transporters expression (GLUT‐1: −4 %, and GLUT‐4: −5.1 %), with no apparent difference in muscular glycogen content. A single bout of exercise increased the glucose transporters (GLUT‐1: +8 %; GLUT‐4: +15 %) as well as FA transporters (FAT/CD36: +13 %; FABPpm: +4.5 %; FATP: +2.5 %, FATP‐4: +10 %) expression but only in WT skeletal muscles. In muscles from IL‐6 KO mice exercise induced changes only in glucose (GLUT‐1: +20 %; GLUT‐4: +35 %) but not in the content of FA transporters. Concomitantly, IL‐6 KO mice displayed shorter time toward exhaustion with more pronounced reductions in intramuscular lipid and glycogen content. We may speculate, that IL‐6 deficiency provokes more pronounced glucose utilization over lipid oxidation during a single bout of exhausting exercise.