Activation of coagulation in C57BL/6 mice given verotoxin 2 (VT2) and the effect of co-administration of LPS with VT2.
To obtain better insight into the pathogenesis of verotoxin-producing Escherichia coli-associated diseases, in this study, we explored the effect of verotoxin 2 (VT2) on coagulation in an animal model. After being given VT2 (50 ng/kg, lethal dose), C57BL/6 mice showed progressively increasing expression of TF mRNA in the kidney and brain and elevated plasma levels of thrombin-antithrombin III complex (TAT), normotest, fibrinogen, and PAI-1 paralleling the disease course over 24 hours; platelet counts were decreased at 48 hours with hemorrhage in the kidney and brain. Co-administration of lipopolysaccharide (LPS, 0.5 mg/kg) with VT2 (50 ng/kg) exhibited more prominant and/or prolonged increase in not only expression of TF and PAI-1 mRNAs in the kidney and brain but also plasma levels of TAT, fibrinogen, and PAI-1 and was associated with more remarkable hemorrhage in the tissues. Although VT2 (5 ng/kg) was not a lethal dose, co-administration of LPS (0.5 mg/kg) with VT2 (5 ng/kg) enhanced the susceptibility to VT2, resulting in more prolonged elevation of TAT levels during the first 24 hours than that in the LPS group and a second elevation at 72 hours, followed by death. Plasma IL-1beta level reached a maximum at 24 hours after VT2 (50 ng/kg) injection prior to the increase in TAT levels, whereas the increase in TNFalpha level immediately after injection was associated with the increase in PAI-1 mRNA. These observations indicate that the activation of coagulation by VT2 may occur through a mechanism different from that used by LPS, since plasma TAT levels rose in the mice immediately after LPS injection and returned to normal over 36 hours.
Sugatani
J
J
Department of Pharmaco-Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
Igarashi
T
T
Munakata
M
M
Komiyama
Y
Y
Takahashi
H
H
Komiyama
N
N
Maeda
T
T
Takeda
T
T
Miwa
M
M
D000818:Animals; D000990:Antithrombin III / Q000187:drug effects; D001777:Blood Coagulation / Q000187:drug effects*; D001780:Blood Coagulation Tests; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D016207:Cytokines / Q000097:blood / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D005340:Fibrinogen / Q000187:drug effects / Q000378:metabolism; D006470:Hemorrhage / Q000139:chemically induced / Q000473:pathology; D020300:Intracranial Hemorrhages / Q000139:chemically induced / Q000473:pathology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008070:Lipopolysaccharides / Q000494:pharmacology* / Q000633:toxicity; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000097:blood*; D023421:Models, Animal; D009504:Neutrophils / Q000166:cytology; D010447:Peptide Hydrolases / Q000187:drug effects; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood / Q000235:genetics; D010976:Platelet Count; D012333:RNA, Messenger / Q000378:metabolism; D022641:Shiga Toxin 2 / Q000494:pharmacology* / Q000633:toxicity; D012769:Shock / Q000139:chemically induced; D013925:Thromboplastin / Q000235:genetics; D013997:Time Factors; D014018:Tissue Distribution
D016207:Cytokines; D008070:Lipopolysaccharides; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger; D022641:Shiga Toxin 2; C046193:antithrombin III-protease complex; D000990:Antithrombin III; D005340:Fibrinogen; D013925:Thromboplastin; D010447:Peptide Hydrolases