[Influence of the escharectomy during stock stage on the peripheral lymphocyte apoptosis and the antigen presentation function of monocytes in peripheral blood of scalded rats].
OBJECTIVE
To investigate the influence of escharectomy at different time-points after burn injury on the lymphocyte apoptosis and the antigen presentation function of monocytes in peripheral blood of scalded rats.


METHODS
One hundred and thirty-six Wistar rats were randomly divided into normal control ( C,n = 8 ), scald ( S, n = 64,without treatment after scald) , A ( n = 40, with escharectomy at 36 post-burn hour( PSH) ) , B ( n = 24, with escharectomy at 72 PSH ) groups. The rats in A , B, S groups were inflicted with 30% TBSA full-thickness scald. The rats in S group were sacrificed on 6,12,24,72,120,168,216, 288 PSH, while those in A and B groups were sacrificed at 72 -288 PSH, 168 -288PSH, respectively. The rats in C group were also sacrificed as control. The apoptotic rate of peripheral lymphocytes, the positive expression rate of MHC- II in mononuclear cells, the changes in concentration of IL-4 and gamma-IFN were determined in each group. The correlation of above indices were also analyzed.


RESULTS
(1) The apoptotic rate of peripheral lymphocyte in S group were increased dramatically at 6PSH, peaking at 24 PSH( 18. 19+/-1.42% ) , then decreasing gradually, reaching the lowest level at 72 PSH(8. 25+/-0.56% ) , then it increased gradually again, approaching almost the peak value at 288 PSH( 17.81 +/- 1.99% ). The values were all obviously higher than those in C group( P <0.05). The apoptotic rates of peripheral lymphocyte in A and B groups were evidently lower than that in S group ( P <0. 01). (2) The positive expression rate of MHC-II in monocyte was decreased sharply at 6 PSH, and it was 20% lower than that in C group (37. 2 +/- 2. 4% ) at 24 PSH. It then increased gradually, but it was significantly lower than that in A, B groups at 288 PSH (18. 8 +/-2. 8, P <0.01). (3) The plasma level of y-IFN in S group increased gradually from 6 PSH on, peaking at 24 PSH(440. 8 +/-25. 1 )ng/L,then decreasing gradually , and it reached the lowest level at 288 PSH (51.3 +/-37.0) ng/L. The IL-4 level in S group was increased gradually ,peaking at 288 PSH (78. 1+/-2. 8) ng/L. (4) There was negative correlation between the expression rate of MHC- II in S group and IL-4/gamma-IFN ratio in escharectomy groups during 72 - 288 PSH ( r = - 0. 96, P < 0. 05).


CONCLUSIONS
Eacharectomy after scald can inhibit peripheral lymphocyte apoptosis, slow down the insertional tendency of IL-4/gamma-IFN , and ameliorate the antigen presentation function of monocytes. Moreover, escharectomy during shock stage can markedly promote the immune function of monocytes.
Liu
Qing-yang
QY
Burn Institute, First Affiliated Hospital to PLA General Hospital, Beijing, PR China.
Hu
Sen
S
Cheng
Ai-guo
AG
Qiu
Fang
F
Pu
Jian-yi
JY
Li
Jun-you
JY
Lv
Yi
Y
Zhou
Guo-yong
GY
Sheng
Zhi-yong
ZY
D000818:Animals; D017951:Antigen Presentation; D017209:Apoptosis; D002056:Burns / Q000276:immunology* / Q000473:pathology / Q000601:surgery; D005802:Genes, MHC Class II; D007371:Interferon-gamma / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology*; D008297:Male; D009000:Monocytes / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D012774:Shock, Traumatic / Q000276:immunology / Q000473:pathology
D015847:Interleukin-4; D007371:Interferon-gamma