title: Cytokine responses to carbohydrate ingestion during recovery from exercise-induced muscle injury.
abstract: We investigated the effect of carbohydrate ingestion after maximal lengthening contractions of the knee extensors on circulating concentrations of myocellular proteins and cytokines, and cytokine mRNA expression in muscle. Using a cross-over design, 10 healthy males completed 5 sets of 10 lengthening (eccentric) contractions (unilateral leg press) at 120% 1 repetition-maximum. Subjects were randomized to consume a carbohydrate drink (15% weight per volume; 3 g/kg BM) for 3 h after exercise using one leg, or a placebo drink after exercise using the contralateral leg on another day. Blood samples (10 mL) were collected before exercise and after 0, 30, 60, 90, 120, 150, and 180 min of recovery. Muscle biopsies (vastus lateralis) were collected before exercise and after 3 h of recovery. Following carbohydrate ingestion, serum concentrations of glucose (30-90 min and at 150 min) and insulin (30-180 min) increased (P < 0.05) above pre-exercise values. Serum myoglobin concentration increased ( approximately 250%; P < 0.05) after both trials. In contrast, serum cytokine concentrations were unchanged throughout recovery in both trials. Muscle mRNA expression for IL-8 (6.4-fold), MCP-1 (4.7-fold), and IL-6 (7.3-fold) increased substantially after carbohydrate ingestion. TNF-alpha mRNA expression did not change after either trial. Carbohydrate ingestion during early recovery from exercise-induced muscle injury may promote proinflammatory reactions within skeletal muscle.
authors.affiliation: Exercise Metabolism Group, School of Medical Sciences, RMIT University , Bundoora, Victoria, Australia.
authors.forename: Megan L R
authors.initials: ML
authors.lastname: Ross
authors.forename: Shona L
authors.initials: SL
authors.lastname: Halson
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Suzuki
authors.forename: Andrew
authors.initials: A
authors.lastname: Garnham
authors.forename: John A
authors.initials: JA
authors.lastname: Hawley
authors.forename: David
authors.initials: D
authors.lastname: Cameron-Smith
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Peake
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000096:biosynthesis / Q000235:genetics; D003289:Convalescence; D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004435:Eating; D015444:Exercise / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000293:injuries / Q000502:physiology; D009135:Muscular Diseases / Q000097:blood / Q000178:diet therapy* / Q000503:physiopathology; D009211:Myoglobin / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D020127:Recovery of Function / Q000187:drug effects; D015854:Up-Regulation
chemical_list: D001786:Blood Glucose; D016207:Cytokines; D004040:Dietary Carbohydrates; D007328:Insulin; D009211:Myoglobin