|
  |
| |
|
| |
Expression
of Tissue Factor and Tissue Factor Pathway Inhibitor in Rat Lungs with Lipopolysaccharide-Induced
Disseminated Intravascular Coagulation |
|
|
Seiichiro Hara,
Yujiro Asada, Kinta Hatakeyama, Kousuke Marutsuka, Yuichiro Sato, Atsushi
Kisanuki, and Akinobu Sumiyoshi |
| |
|
| |
First
Department of Pathology, Miyazaki Medical College, Miyazaki, Japan |
| |
|
| |
Disseminated intravascular
coagulation (DIC) is a frequent complication of endotoxin shock, and modulation
of endothelial cell hemostatic properties has been proposed to play an important
role in its onset. We examined the in vivo expression of tissue factor (TF)
and TF pathway inhibitor (TFPI) in rat lungs of a lipopolysaccharide (LPS)-induced
DIC model. Light and electron microscopic studies showed that fibrin-rich
thrombi were present in the pulmonary microvasculature 3 hours after intraperitoneal
injection of LPS (7.5 mg/kg) and increased in number at 6 hours. In an immunohistochemical
study, an increase in number of monocytes in the microvasculature was observed
after LPS injection, and many of these cells (> 90%) were positive for
TF antigen. However, no TF expression in endothelial cells was detected.
Pulmonary endothelial cells showed positive reaction for TFPI antigen before
LPS injection, but TFPI-positive endothelial cells markedly decreased in
number after LPS injection. mRNA expression of TF increased and that of
TFPI decreased in the lung tissue 3 and 6 hours after LPS injection. High
values of TF activity were detected in the lung tissue and plasma, whereas
TFPI activities decreased after LPS injection. These results indicate that
imbalance between TF and TFPI, overexpression of TF, and underexpression
of TFPI in the lung may contribute to thrombus formation in this LPS-induced
DIC model. |
| |
|
| |
 |
