[The effects of gut -- origin lipopolysaccharide translocation on the apoptosis of lymphocytes in scalded rats].
OBJECTIVE
To investigate the relationship between lymphocyte apoptosis in spleen and mesenteric lymph nodes (MLNs) and gut -- origin lipopolysaccharide (LPS) translocation after severe scalding in rats.


METHODS
Wistar rats inflicted 30% TBSA III degree scalding were employed as the model. Serum LPS levels in portal vein and vena cava were determined by limulus amebocyte lysate (LAL) test. Apoptotic lymphocytes in paraffin -- embedded spleen and MLNs sections were detected with TdT -- mediated and dUTP nick end labeling (TUNEL) and peroxidase (POD) staining. The images were taken by cooldccd camera system, and the count and optical density (OD) value of apoptotic lymphocytes were analyzed with software Spot and Imagine proplus 4.10a (IPP4.10a).


RESULTS
Serum LPS levels in portal vein and vena cava increased sharply in rats postburn (P < 0.01) and reached a peak value at 6 postburn hour (PBH). LPS level in portal vein was higher than that in vena cava (P < 0.01) in the period of 3 to 48 PBHs. The results of TUNEL -- POD staining and the count of apoptotic lymphocytes showed that the apoptotic cells were few in normal MLNs, but increased obviously postburn (P < 0.01), especially at 3 PBH. On the contrary, apoptotic lymphocytes were concentrated in spleen cortex before injury and decreased obviously postburn (P < 0.01), though a slight recovery was found after 24 PBH. Optical density of apoptotic lymphocytes was significantly reduced in spleen at 24 PBH, But the OD value of apoptotic lymphocytes in MLNs increased significantly within 48 PBHs when compared with that before injury (P < 0.01).


CONCLUSIONS
Gut -- origin endotoxemia in rat could occur in early postburn period. The LPS translocation might induce lymphocyte apoptosis in MLNs. The decreased apoptotic lymphocytes in spleen implied abnormal immune function in spleen.
Xia
P
P
Institute of Burn Research, Southwestern Hospital, The third Military Medical University, Chongqing 400038 P. R. China.
Zheng
J
J
Zhou
H
H
Pan
W
W
Qin
X
X
Xiao
G
G
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001692:Biological Transport; D002056:Burns / Q000097:blood / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D007413:Intestinal Mucosa / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000097:blood / Q000378:metabolism*; D008214:Lymphocytes / Q000166:cytology / Q000502:physiology*; D008297:Male; D011169:Portal Vein / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014684:Venae Cavae / Q000378:metabolism
D008070:Lipopolysaccharides