[Early changes in serum neutrophil elastase in rats with burn, blast injury or combined burn-blast injury and its significance].
OBJECTIVE
To explore the early changes in serum neutrophil elastase (NE) in rats with burn, blast injury or combined burn-blast injury and its significance.


METHODS
A total of 176 male Sprague Dawley rats were randomly divided into four groups: control (C), burn (BU), blast injury (BL) and burn-blast combined injury (BB). Rats in C group were not injured. Animals in BU group were subjected to 25% TBSA full-thickness burn on back with 94 degrees C water for 12 seconds; Animals in BL group were inflicted with moderate blast injury with 5 g 8701 compressed dynamite stick as the explosion source 75 cm away while left chest facing the explosive source; Rats in BB group were burned immediately after the blast injury similarly as in BL group. During the first 24 h post-injury, animals in BU and BB groups received intraperitoneal injection of sodium lactate Ringer's solution at a dose of 50 ml x kg(-1) x 12 h(-1). Protein concentration in bronchoalveolar lavage fluid (BALF), water content of lung tissue and NE content in serum were determined at 0 h (C group), 3 h, 6 h, 12 h, 1 d, 2 d, 3 d, 7 d post-injury.


RESULTS
Protein concentration in BALF, water content of lung tissue and NE content in serum in SD rats of the injured groups were significantly higher than those in C group (P < 0.01 or P < 0.05), peaked within 2 d post-injury, especially at 2 d post-injury (NE content in serum: BU group, 319. 85 +/- 19.50 ng/ml; BL group, 467.43 +/- 31.64 ng/ml; BB group, 626.00 +/- 26.38 ng/ml vs. C group, 78.53 +/- 25.10 ng/ml). Overall, protein concentration in BALF, water content of lung tissue and NE content in serum in BB group were significantly higher than BU and BL groups (P < 0.01 or P < 0.05). Correlation analysis showed that within 3 d postinjury, a significant positive correlation was found between the protein concentration in BALF, water content of lung tissue and NE content in serum (r = 0.7910, 0.8078, P < 0.05) in BU group. NE content in serum and protein concentration in BALF were significantly positively correlated in BB group (r = 0.8672, P < 0.05).


CONCLUSIONS
NE may play an important role in early lung injury of burn or blast injury, especially in combined burn-blast injury.
Cai
Jian-hua
JH
Department of Burn & Plastic Surgery, First Hospital Affiliated to PLA General Hospital, Beijing, China.
Chai
Jia-ke
JK
Shen
Chuan-an
CA
Yin
Hui-nan
HN
Zhou
Xiao-fang
XF
Lu
Wei
W
Hu
Qing-gang
QG
Chi
Yun-fei
YF
Ma
Li
L
Deng
Hu-ping
HP
Zhang
Xi-bo
XB
Sun
Tian-jun
TJ
Han
Yan-fu
YF
D000818:Animals; D002056:Burns / Q000097:blood*; D004195:Disease Models, Animal; D019272:Leukocyte Elastase / Q000097:blood*; D055370:Lung Injury / Q000097:blood*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014947:Wounds and Injuries / Q000097:blood*
D019272:Leukocyte Elastase