title: A single bout of exercise increases the expression of glucose but not fatty acid transporters in skeletal muscle of IL-6 KO mice.
abstract: 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.
authors.affiliation: Department of Physiology, Medical University of Bialystok, ul. Mickiewicza 2C, Bialystok, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Lukaszuk
authors.forename: I
authors.initials: I
authors.lastname: Bialuk
authors.forename: J
authors.initials: J
authors.lastname: Górski
authors.forename: M
authors.initials: M
authors.lastname: Zajączkiewicz
authors.forename: M M
authors.initials: MM
authors.lastname: Winnicka
authors.forename: A
authors.initials: A
authors.lastname: Chabowski
mesh_terms: D000263:Adenylate Kinase / Q000096:biosynthesis; D000818:Animals; D018955:CD36 Antigens / Q000096:biosynthesis; D050612:Fatty Acid Transport Proteins / Q000096:biosynthesis; D050556:Fatty Acid-Binding Proteins / Q000096:biosynthesis*; D051272:Glucose Transporter Type 1 / Q000096:biosynthesis*; D051275:Glucose Transporter Type 4 / Q000096:biosynthesis*; D015850:Interleukin-6 / Q000172:deficiency*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018482:Muscle, Skeletal / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D013550:Swimming
chemical_list: D018955:CD36 Antigens; D050612:Fatty Acid Transport Proteins; D050556:Fatty Acid-Binding Proteins; D051272:Glucose Transporter Type 1; D051275:Glucose Transporter Type 4; D015850:Interleukin-6; C493569:Slc27a1 protein, mouse; C493572:Slc27a4 protein, mouse; C495678:Slc2a1 protein, mouse; C495693:Slc2a4 protein, mouse; D000263:Adenylate Kinase