Carbohydrate ingestion influences skeletal muscle cytokine mRNA and plasma cytokine levels after a 3-h run.
Sixteen experienced marathoners ran on treadmills for 3 h at approximately 70% maximal oxygen consumption (Vo(2 max)) on two occasions while receiving 1 l/h carbohydrate (CHO) or placebo (Pla) beverages. Blood and vastus lateralis muscle biopsy samples were collected before and after exercise. Plasma was analyzed for IL-6, IL-10, IL-1 receptor agonist (IL-1ra), IL-8, cortisol, glucose, and insulin. Muscle was analyzed for glycogen content and relative gene expression of 13 cytokines by using real-time quantitative RT-PCR. Plasma glucose and insulin were higher, and cortisol, IL-6, IL-10, and IL-1ra, but not IL-8, were significantly lower postexercise in CHO vs. Pla. Change in muscle glycogen content did not differ between CHO and Pla (P = 0.246). Muscle cytokine mRNA content was detected preexercise for seven cytokines in this order (highest to lowest): IL-15, TNF-alpha, IL-8, IL-1beta, IL-12p35, IL-6, and IFN-gamma. After subjects ran for 3 h, gene expression above prerun levels was measured for five of these cytokines: IL-1beta, IL-6, and IL-8 (large increases), and IL-10 and TNF-alpha (small increases). The increase in mRNA (fold difference from preexercise) was attenuated in CHO (15.9-fold) compared with Pla (35.2-fold) for IL-6 (P = 0.071) and IL-8 (CHO, 7.8-fold; Pla, 23.3-fold; P = 0.063). CHO compared with Pla beverage ingestion attenuates the increase in plasma IL-6, IL-10, and IL-1ra and gene expression for IL-6 and IL-8 in athletes running 3 h at 70% Vo(2 max) despite no differences in muscle glycogen content.
Nieman
D C
DC
Department of Health, Fischer Hamilton/Nycom Biochemistry Laboratory, Appalachian State University, Boone, North Carolina 28608, USA. niemandc@appstate.edu
Davis
J M
JM
Henson
D A
DA
Walberg-Rankin
J
J
Shute
M
M
Dumke
C L
CL
Utter
A C
AC
Vinci
D M
DM
Carson
J A
JA
Brown
A
A
Lee
W J
WJ
McAnulty
S R
SR
McAnulty
L S
LS
D000328:Adult; D001772:Blood Cell Count; D001786:Blood Glucose / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis* / Q000097:blood* / Q000235:genetics; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression; D006003:Glycogen / Q000378:metabolism; D006728:Hormones / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007070:Immunoglobulin A / Q000032:analysis / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D012420:Running / Q000502:physiology*; D012463:Saliva / Q000737:chemistry / Q000276:immunology
D001786:Blood Glucose; D016207:Cytokines; D018076:DNA, Complementary; D004040:Dietary Carbohydrates; D006728:Hormones; D007070:Immunoglobulin A; D012333:RNA, Messenger; D006003:Glycogen; D006854:Hydrocortisone