Neutrophil margination and extravasation in sinusoids and venules of the liver during endotoxin-induced injury. Chosay, John G., Naeem A. Essani, Colin J. Dunn, and Hartmut Jaeschke. Cell Biology and Inflammation Research and Cardiovascular Pharmacology, Pharmacia & Upjohn, Inc., Kalamazoo, Michigan 49007
APStracts 3:0270G, 1996.
Neutrophils contribute to liver damage during endotoxin shock. The objective of this investigation was to document where neutrophil localize in the hepatic vasculature and if they migrate out of sinusoids or postsinusoidal venules using a well-characterized model of galactosamine/endotoxin shock and immunostaining for neutrophil -associated MRP8/MRP14 S100 calcium binding proteins. Treatment of C3Heb/FeJ mice with 100 [mu]g/kg Salmonella abortus equi endotoxin alone or in combination with 700 mg/kg galactosamine induced a time -dependent increase of neutrophil margination in sinusoids and postsinusoidal venules at 4 h. The number of venular neutrophils decreased in both groups at later time points without evidence for transmigration. Extravasation of neutrophils was only observed from sinusoids in galactosamine/endotoxin-treated animals between 4-7h, which correlated with parenchymal cell injury. After endotoxin alone, large numbers of neutrophils remained sequestered in sinusoids without injury. These data suggest that neutrophils cause hepatocellular injury during endotoxemia after extravasation and are less likely to cause damage when sequestered in the vasculature. In the liver, neutrophils migrate out of sinusoids and not out of postsinusoidal venules.

Received 31 May 1996; accepted in final form 25 November 1996.
APS Manuscript Number G218-6.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996