Modulation of disseminated intravascular coagulation (DIC) by steroidal and non-steroidal anti-inflammatory drugs

Combination therapy of Ulinastatin with Thrombomodulin alleviates endotoxin (LPS) - induced liver and kidney injury via inhibiting apoptosis, oxidative stress and HMGB1/TLR4/NF-κB pathway

Sepsis is a type of systemic inflammation response syndrome that leads to organ function disorders. Currently, there is no specific medicine for sepsis in clinical practice. Lipopolysaccharide (LPS) is an important endotoxin that causes sepsis. Here, we report an effective two-drug combination therapy to treat LPS-induced liver and kidney injury in endotoxic rats. Ulinastatin (UTI) and Thrombomodulin (TM) are biological macromolecules extracted from urine. In our study, combination therapy significantly improved LPS-induced liver and kidney pathological structure and functional injury, and significantly improved the survival rate of endotoxic rats. Results of TUNEL staining and Western blot showed that UTI combined with TM inhibited the excessive apoptosis of liver and kidney cells caused by LPS. The drug combination also promoted the proliferation of liver and kidney cells, reduced the levels of pro-inflammatory factors interleukin (IL)-6, IL-1β, tumor or necrosis factor (TNF)-α and nitric oxide, and down-regulated the expression of High Mobility Group Box 1 (HMGB1), Toll-like receptor (TLR) 4 and Nuclear Factor (NF)-κB phosphorylation to inhibit inflammation. In addition, the combination of UTI and TM also promoted the production of a variety of antioxidant enzymes in the tissues and inhibited the production of lipid peroxidation malondialdehyde (MDA) to enhance antioxidant defenses. Our experiments also proved that UTI combined with TM did not reduce the anticoagulant effect of TM. These results suggested that UTI combined with TM can improve endotoxin-induced liver and kidney damage and mortality by inhibiting liver and kidney cell apoptosis, promoting proliferation, and inhibiting inflammation and oxidative injury.

Salutary effects of the prostacyclin analogue CG 4203 in lethal endotoxemia in rats

In pentobarbitone anesthetized rats infusion of E. coli endotoxin (0.42 mg.kg-1.min-1 for 4 hours) produced 96% lethality within 6 hours. Transient decrease in mean arterial blood pressure, thrombocytopenia, leukopenia, loss of plasma fibrinogen, fibrin deposits in renal glomeruli, hemolysis and decrease in arterial oxygen tension and pH were observed. Infusion of the prostacyclin analogue CG 4203 (0.464 and 1.0 micrograms.kg-1.min-1 for 6 hours), starting concomitantly with the endotoxin infusion, improved the survival rate to 95 and 100%. Blood pressure during endotoxemia was slightly lower in CG 4203 treated rats than in vehicle controls. CG 4203 infusion marginally attenuated thrombocytopenia and obviously inhibited leukopenia, but did not effect fibrinogen consumption in endotoxemic rats. Incidence of glomerular fibrin deposits was dose dependently and significantly reduced by CG 4203. The lower dose reduced and the higher dose completely prevented the occurrence of hemolysis. Acidotic changes were not observed in CG 4203 treated endotoxin-shocked rats. Also with treatment starting 1 hour after the onset of endotoxemia CG 4203 in the same doses significantly inhibited the endotoxin-induced lethality. As protective mechanisms against lethal rat endotoxemia the prostacyclin-like hemodynamic, fibrinolytic, rheological and membrane stabilizing properties of CG 4203 are discussed.

Disseminated intravascular coagulation

Etiology, pathogenesis, clinical features, laboratory findings, and therapy of disseminated intravascular coagulation (DIC) in the dog and the cat are reviewed.

Studies on the vascular and hematological changes induced by ellagic acid in rats

We compared the major changes induced by ellagic acid (EA), a Hageman factor activator, in normal rats and in kininogen-deficient Brown Norway rats. In normal rats, large doses of EA induced a congestion of lymph nodes, spleen and liver, a prolongation of activated partial thromboplastin time, the consumption of prekallikrein, high molecular weight kininogen and fibrinogen, as well as the stimulation of platelets with their accumulation in lungs, liver and spleen. A systemic hypotension of long duration was also observed. The fibrinogen consumption, the thrombocytopenia and the lengthening of activated partial thromboplastin time were dose-dependent. In kininogen-deficient rats, EA induced only a minimal congestion of lymphoid tissues, the accumulation of platelets in lungs, a decrease of plasma fibrinogen and a short-lasting hypotension. It is concluded that the vascular changes induced by blood coagulation with ellagic acid resulted mainly from kinin formation.

Vasoactive agents and production of thrombosis during intravascular coagulation. 2. alpha-Adrenergic stimulation: effects and mechanisms

The mechanism whereby norepinephrine elicits thrombosis during intravascular coagulation was investigated further in rabbits given a 4 h infusion of thrombin (1 NIH unit/kg/min). Norepinephrine (3 micrograms/kg/min) combined with thrombin produced glomerular capillary thrombosis in all animals as compared to 4.3% with thrombin alone. Alpha-adrenergic receptors mediated this effect, as indicated (a) by prevention of glomerular thrombosis by dibenzyline but not by methysergide, and (b) by failure of histamine or acetylcholine combined with thrombin to induce the phenomenon. However, in combination with thrombin, these two agents induced duodenal mucosal microthrombosis. Study of the glomerular circulation with colloidal carbon showed that norepinephrine elicits severe glomerular capillary stasis in thrombin treated rabbits; the vasomotor reaction precedes increased fibrinogen consumption and focal deposition of fibrin in the glomeruli. Pretreatment with dibenzyline prevented glomerular stasis and reduced fibrinogen consumption. The phagocytic activity of the reticulo-endothelial system was increased 7 times by thrombin infusions, with or without norepinephrine. We conclude that stimulation of the alpha 1-adrenergic receptors triggers glomerular thrombosis by production of severe glomerular stasis which localizes formation of thrombi in the dilated vessels. These results provide a rational explanation for the role of alpha-adrenergic stimulation in the endotoxin-induced generalized Shwartzman reaction and outline some of the mechanisms and agents implied in the selection of the target organs for thrombosis during intravascular coagulation.

Vasoactive agents and production of thrombosis during intravascular coagulation 1--comparative effects of norepinephrine in thrombin and adenosine diphosphate (ADP) treated rabbits

Pathogenesis of the microthrombi produced during intravascular coagulation was investigated in rabbits given intravenous infusions of thrombin or adenosine diphosphate (ADP). Thrombin, at a dosage producing a fibrinogen consumption of 70% within 4 h (1 unit/kg/min), failed to produce extrapulmonary microthrombi unless fibrinolysis inhibition (epsilon-aminocaproic acid-EACA) or alpha-adrenergic stimulation (norepinephrine) were provided simultaneously. The mechanism whereby norepinephrine initiated glomerular capillary thrombosis was not related to interference with fibrinolysis nor to potentiation of platelet aggregation and blood coagulation, as indicated by similar consumption of plasminogen and platelets in animals given thrombin alone or combined with norepinephrine, and by the lack of correlation between fibrinogen consumption and the incidence and severity of glomerular thrombosis produced with various dosages (1 to 3 mu/kg/min) of norepinephrine. With norepinephrine, microthrombi were also observed in the adrenals, the spleen and the gastric mucosa. Aspirin prevented the phenomena in the latter two organs, but was inactive or aggravating on thrombogenesis elsewhere. ADP associated with thrombin failed to trigger formation of microthrombi but initiated platelet-rich thrombi in the pulmonary vasculature when associated with norepinephrine. We conclude that unlike thrombin, ADP cannot be held responsible for the microthrombi elicited during experimental intravascular coagulation. Furthermore, the ability of norepinephrine to elicit glomerular thrombosis in thrombin injected rabbits may provide an explanation for requirement of alpha-adrenergic stimulation in the endotoxin-induced generalized Shwartzman reaction.