Arginine-supplemented diet decreases expression of inflammatory cytokines and improves survival in burned rats.
BACKGROUND
We examined whether the expression of inflammatory cytokines in organs was influenced by the enteral diet supplemented with arginine in burned rats.


METHODS
Male Wistar rats weighing about 200 g underwent catheter jejunostomy and received scald burns covering 30% of the whole-body surface area. Animals were divided into two groups: a control group (no supplemental arginine, n = 12) and an arginine group (supplemental arginine: 7.7 g/L, n = 10), which continuously received total enteral nutrition for 7 days (250 kcal/kg/d, 1.72 gN/kg/d). The following were measured after the experiment: (1) messenger RNA (mRNA) expression of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta), and IL-6 in the spleen, thymus, lung, and liver by a semiquantitative reverse transcription-polymerase chain reaction method, (2) inflammatory cytokines in the plasma and supernatant of cultured splenic lymphocytes by enzyme-linked immunosorbant assay, (3) nitric oxide (NO) product, NO2-/NO3-, in the plasma and supernatant of cultured splenic lymphocytes by the Griess method, and (4) survival rate by the Kaplan-Meier method.


RESULTS
The mRNA expression of TNF-alpha was significantly decreased in the spleen and lung (p < .01, p < .05), IFN-gamma in the lung (p < .05), IL-1beta in the spleen (p < .05), and IL-6 in the thymus and liver (p < .05, p < .05) in the arginine group when compared with the control group. The production of TNF-alpha by splenic lymphocytes was suppressed in the arginine group in both concanavalin A (Con A)-treated and -untreated cultures (p < .01, p < .05). The production of IFN-gamma by splenic lymphocytes treated with Con A was suppressed in the arginine group (p < .05). The NO product in the supernatant without Con A was increased in the arginine group (p < .05). The mortality rate of the arginine group (0%) was lower than that in the control group (33.3%) on day 7 after the burn injury (p < .05).


CONCLUSIONS
The data suggest that dietary arginine supplementation decreases the mRNA expression of inflammatory cytokines in organs and improves the survival rate after thermal injury.
Cui
X L
XL
Department of Surgery II, Kochi Medical School, Nankoku, Japan.
Iwasa
M
M
Iwasa
Y
Y
Ogoshi
S
S
D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects; D002056:Burns / Q000188:drug therapy* / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D004032:Diet; D004750:Enteral Nutrition; D007371:Interferon-gamma / Q000097:blood; D007378:Interleukins / Q000097:blood*; D007582:Jejunostomy; D008099:Liver / Q000033:anatomy & histology / Q000187:drug effects / Q000276:immunology; D008168:Lung / Q000033:anatomy & histology / Q000187:drug effects / Q000276:immunology; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000033:anatomy & histology / Q000187:drug effects / Q000276:immunology; D013950:Thymus Gland / Q000187:drug effects / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D014945:Wound Healing / Q000187:drug effects
D007378:Interleukins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D003208:Concanavalin A; D009569:Nitric Oxide; D007371:Interferon-gamma; D001120:Arginine