[An experimental study on the apoptosis of PMNs and macrophages during the early postburn stage in severely scalded rats].
OBJECTIVE
To investigate the changes of postburn apoptosis of PMN and the apoptosis of PMN and macrophages after being stimulated by burn sera and the change of the phagocytosis of apoptotic PMNs by macrophages.


METHODS
Rats inflicted by 30% TBSA III degree scalding were employed as the model. PMNs were harvested on the 0, 6, 12 and 24 postburn hour (PBH). Burn sera were harvested at 24 PBHs. PMN apoptosis was detected by flow cytometry. Simultaneously, peritoneal macrophages were collected for the study. The apoptotic change of the macrophages (Mphis) after being stimulated by burn sera and the ability of Mphis phagocytizing apoptotic PMNs at 24 PBHs were examined.


RESULTS
The PMN apoptosis was obviously inhibited at 6, 12 and 24 PBHs in the scalded rats with no difference between the time spots. Twenty-four hours after being stimulated by burn sera, the apoptotic rate of PMNs on scalded rats was lower than that in normal rats, while the apoptotic rate of Mphis in scalded rats was higher than that in normal rats. The ability of Mphis phagocytizing apoptotic PMNs decreased after severe burn (P < 0.01).


CONCLUSIONS
There exhibited delayed rat PMN apoptosis and decreased ability of the phagocytosis of apoptotic PMNs by the Mphis after severe burn or being stimulated by burn sera. This might lead to the incomplete phagocytosis of apoptotic PMNs by Mphis. As a result, the PMNs would finally come to necrosis and release toxic contents which were important factors in the inducing of SIRS.
Li
Z
Z
Institucte of Burn Research, Southwestern Hospital, The Third Military Medical University, Chongqing, 400038, P.R. China.
Huang
Y
Y
Yang
Z
Z
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002056:Burns / Q000097:blood / Q000503:physiopathology*; D005434:Flow Cytometry; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000502:physiology*; D009504:Neutrophils / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar