[Study on the mechanism of protective effect of oral L-arginine on intestine after scald injury in rats].
OBJECTIVE
To explore the mechanism of protective effect of oral L-arginine (L-Arg) on the intestine after scald injury in rats.


METHODS
Sixty-six Sprague-Dawley (SD) rats were randomly divided into three groups: i.e. normal control (N, n = 6, without treatment), oral L-arginine group (A, n = 30, with 1 ml 70 g/L of L-Arg per os 2 times a day from 2 post scald hour (PSH)) on with normal enteral feeding and group B (n = 30, with oral feeding of cold boiled water after scald). The changes in the content of superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO), endothelin (ET), ET/NO ratio in the intestine and the level of plasma endotoxin (LPS) in portal vein were assessed at 6, 12, 24, 48, 72 PSH. Ileum tissue samples were harvested for pathological examination.


RESULTS
The ET content in the intestinal tissue in A group at 6, 12 and 24 PSH (0.80 +/- 0.26 ng/g, 0.75 +/- 0.30 ng/g, 0.63 +/- 0.22 ng/g) was obviously lower than that in B group (1.26 +/- 0.38 ng/g, 1.34 +/- 0.37 ng/g, 0.97 +/- 0.19 ng/g, P < 0.05), but the NO contents in the intestine in A group at the same time points were significantly higher than that in B group (P < 0.01). The ET/NO ratio and the level of plasma endotoxin in A group were significantly lower than those in B group at each time point (P < 0.05 or 0.01). Pathological examination showed that the intestinal mucosal injury in the A group was obviously milder than that in the B group.


CONCLUSIONS
Oral L-arginine was shown to have the effects to ameliorate ischemia reperfusion injury of the intestine and to protect the barrier function of the intestinal mucosa. This might be related to an increase in the NO level in intestinal mucosa resulting in maintenance of a stable ET/NO ratio.
Chen
Bin
B
Department of Burns, The Second Affiliated Hospital of Kunming Medical College, Kunming 650101, P. R. China.
Fu
Jin-feng
JF
Yuan
Wei-hong
WH
Xu
Yan
Y
Luo
Zhi-hang
ZH
Wang
Hong
H
Chen
Zong-hua
ZH
Li
Cui-ping
CP
D000818:Animals; D001120:Arginine / Q000494:pharmacology* / Q000627:therapeutic use; D002056:Burns / Q000378:metabolism* / Q000628:therapy; D004195:Disease Models, Animal; D016232:Endothelins / Q000378:metabolism; D005248:Feeding Methods; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000503:physiopathology; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000378:metabolism* / Q000628:therapy
D016232:Endothelins; D009569:Nitric Oxide; D001120:Arginine