Peritoneal inflammatory cells in acute pancreatitis: Relationship of infiltration dynamics and cytokine production with severity of illness.
BACKGROUND
The purpose of this study was to clarify the still poorly understood dynamics of peritoneal inflammatory cells (PICs) in acute pancreatitis.


METHODS
Acute pancreatitis of 3 different degrees of severity was induced in male Wistar rats. Peritoneal lavage was performed at 1, 6, 12, and 24 hours after the induction, and the fluids collected were analyzed for the number and subpopulation of PICs. The levels of apoptosis and necrosis, cytokines, and bacterial infection were also investigated.


RESULTS
The number of PICs was increased in mild and moderate pancreatitis, and the infiltration of inflammatory cells had occurred. In severe pancreatitis, the number of PICs increased until 6 hours after the induction, but thereafter the number decreased. Infiltration of neutrophils occurred 6 hours after the induction, but it was not sustained thereafter and infiltration of peritoneal macrophages did not occur. Cytokines in the lavage fluid increased in all 3 models during the first 6 hours after the induction. Subsequently, cytokines were reduced in mild and moderate pancreatitis but significantly increased in severe pancreatitis. The level of bacterial infection increased according to the severity.


CONCLUSIONS
The relationship between the PIC dynamics and cytokine levels in severe pancreatitis is very different from that observed in mild or moderate pancreatitis.
Mikami
Yukio
Y
Department of Surgery, Tohoku University School of Medicine, Sendai and Miyagi, Japan.
Takeda
Kazunori
K
Shibuya
Kazuhiko
K
Qiu-Feng
Huang
H
Egawa
Shinichi
S
Sunamura
Makoto
M
Matsuno
Seiki
S
D000208:Acute Disease; D000818:Animals; D001202:Ascitic Fluid / Q000737:chemistry / Q000473:pathology; D002452:Cell Count; D005434:Flow Cytometry; D007375:Interleukin-1 / Q000032:analysis*; D017737:Macrophages, Peritoneal / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009504:Neutrophils / Q000378:metabolism / Q000473:pathology*; D010179:Pancreas / Q000473:pathology; D010195:Pancreatitis / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D010533:Peritoneal Lavage; D010537:Peritoneum / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha