No interplay between the pathways mediating coagulation and inflammation in tissue factor-induced disseminated intravascular coagulation in rats.

Objective: Previous reports have suggested an interplay between the pathways mediating coagulation and inflammation in endotoxemia and sepsis. The present study was designed to examine whether cross-signaling between the pathways mediating coagulation and inflammation occurs, as suggested by the pattern of cytokine production observed following tissue-factor (TF)-induced disseminated intravascular coagulation (DIC). Design: Prospective, comparative, experimental study. Setting: Laboratory at a university hospital. Subjects: Male Wistar rats, aged 6-7 wks, and weighing 160-170 g. Interventions: Male Wistar rats were administered TF (3.75 units/kg every 4 hrs), TF, and tranexamic acid (TA; 50 mg/kg every 4.5 hrs) or lipopolysaccharide (30 mg/kg every 4 hrs) via the tail vein, and blood was sampled at 0, 4, 8 and 12 hrs. Measurements and Main Results: Subsequent alterations in thrombin-antithrombin complex and fibrinogen levels, as well as platelet counts, indicated that the severity of both types of experimental DIC (TF-induced and lipopolysaccharide-induced) was similar with respect to hemostatic activation and development of consumption coagulopathy. In lipopolysaccharide-induced DIC, a sharp increase in plasma tumor necrosis factor levels was observed at 4 hrs, after which a sharp decline was noted. Plasma levels of interleukin-6 were markedly increased at 4 hrs, after which a sustained elevation was observed for the duration of the experimental period (tumor necrosis factor, 1270 ± 280,180 ± 40, and 120 ± 30 pg/mL at 4, 8 and 12 hrs, respectively; interleukin-6, 5810 ± 1320, 4850 ± 730, and 5230 ± 1280 pg/mL at 4, 8 and 12 hrs, respectively). On the other hand, tumor necrosis factor and interleukin-6 were not detected following TF-induced DIC (0 ± 0 at 4, 8, and 12 hrs for both tumor necrosis factor and interleukin-6). In the TF+TA group, significant increases in tumor necrosis factor and interleukin-6 were observed, compared with the TF group. Conclusions: There is no overt interplay between the pathways mediating coagulation and inflammation in TF-induced DIC, as observed in lipopolysaccharide-induced DIC.