Neutrophils and NADPH oxidase mediate intrapancreatic trypsin activation in murine experimental acute pancreatitis.
OBJECTIVE
Intrapancreatic activation of digestive enzymes is a key event in the parenchymal cell injury of pancreatitis. We hypothesized that neutrophils recruited to the pancreas during pancreatitis may contribute to such activation.


METHODS
To cause experimental pancreatitis, rats and mice were treated with high doses of cerulein. Activation of the digestive enzyme, trypsin, was measured in pancreatic homogenates using a fluorogenic assay and localized immunocytochemically with antibody to trypsin-activation peptide (TAP).


RESULTS
Compared with controls, rats depleted of neutrophils with antineutrophil serum exhibited a marked attenuation in intrapancreatic trypsin activation and acinar cell TAP labeling induced by high-dose cerulein. To examine the mechanism, mice deficient in either nicontinamide adenine dinucleotide phosphate (NADPH) oxidase, or myeloperoxidase (MPO) were studied for trypsin activation. Mice deficient in NADPH oxidase exhibited attenuation of the cerulein-induced trypsin activation, but those deficient in MPO did not. Using measurements of Western blot analysis, generation of reactive oxygen species, and immunocytochemistry, we demonstrated the NADPH oxidase activity is in neutrophils and not pancreatic acinar tissue.


CONCLUSIONS
The results demonstrate a novel role for neutrophils infiltrating the pancreas in pathologic activation of digestive enzymes in acute pancreatitis and indicate that this effect is mediated by products of NADPH oxidase.
Gukovskaya
Anna S
AS
Department of Medicine, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California 90073, USA. agukovsk@ucla.edu
Vaquero
Eva
E
Zaninovic
Vjekoslav
V
Gorelick
Fred S
FS
Lusis
Aldons J
AJ
Brennan
Marie-Luise
ML
Holland
Steven
S
Pandol
Stephen J
SJ
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002108:Ceruletide; D004789:Enzyme Activation / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism*; D009504:Neutrophils / Q000201:enzymology* / Q000276:immunology; D010179:Pancreas / Q000201:enzymology; D019283:Pancreatitis, Acute Necrotizing / Q000139:chemically induced / Q000276:immunology* / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014357:Trypsin / Q000378:metabolism*
D000906:Antibodies; D010750:Phosphoproteins; D002108:Ceruletide; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D014357:Trypsin