RESUMEN
OBJECTIVE: Sepsis, a leading cause of mortality in critically ill patients, is closely linked to the excessive activation of coagulation and inflammation. Protein Z, a cofactor for the protein Z-dependent protease inhibitor, enhances the inhibition of coagulation factor Xa, and protein Z-dependent protease inhibitor inhibits factor XIa in a protein Z-independent fashion. The functions of protein Z and protein Z-dependent protease inhibitor in the inflammatory and coagulant responses to septic illness have not been evaluated. DESIGN: For induction of generalized Shwartzman reaction, dorsal skinfold chamber-equipped mice were challenged twice with lipopolysaccharide (0.05 mg/kg on day -1 and 5 mg/kg body weight 24 hr later). Time-matched control animals received equal volumes of saline. SETTING: University research laboratory. SUBJECTS, INTERVENTIONS, AND MEASUREMENTS: Using intravital fluorescence microscopy in protein Z-dependent protease inhibitor deficient (ZPI) and protein Z deficient (PZ) mice, as well as their wild-type littermates (ZPI, PZ), kinetics of light/dye-induced thrombus formation and microhemodynamics were assessed in randomly chosen venules. Plasma concentrations of chemokine (C-X-C motif) ligand 1, interleukin-6, and interleukin-10 were measured. Liver and lung were harvested for quantitative analysis of leukocytic tissue infiltration and thrombus formation. MAIN RESULTS: After induction of generalized Shwartzman reaction, all mice showed significant impairment of microhemodynamics, including blood flow velocity, volumetric blood flow, and functional capillary density, as well as leukocytopenia and thrombocytopenia. Thrombus formation time was markedly prolonged after induction of generalized Shwartzman reaction in all mice, except of ZPI mice, which also had a significantly higher fraction of occluded vessels in liver sections. PZ mice developed the highest concentrations of interleukin-6 and interleukin-10 in response to generalized Shwartzman reaction and showed greater leukocytic tissue infiltration than their wild-type littermates. CONCLUSIONS: In this murine model of generalized Shwartzman reaction, protein Z-dependent protease inhibitor deficiency enhanced the thrombotic response to vascular injury, whereas protein Z deficiency increased inflammatory response.
Asunto(s)
Proteínas Sanguíneas/fisiología , Serpinas/fisiología , Fenómeno de Shwartzman/fisiopatología , Animales , Velocidad del Flujo Sanguíneo , Proteínas Sanguíneas/genética , Quimiocina CXCL1/sangre , Genotipo , Interleucina-1/sangre , Interleucina-10/sangre , Leucopenia/sangre , Lipopolisacáridos , Hígado/patología , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Serpinas/genética , Fenómeno de Shwartzman/sangre , Fenómeno de Shwartzman/inducido químicamente , Trombocitopenia/sangre , Trombosis/sangre , Trombosis/etiología , Vénulas/fisiologíaRESUMEN
The impact of clot stability affecting the vasculopathy and tissue necrosis in Shwartzman reaction was investigated using plasma Factor XIII A2-depleted rabbit (FXIII-DR). Plasma Factor XIIIA2 (FXIIIA2) was depleted by infusion of the mono-specific goat anti-rabbit FXIIIA2 IgG. Generalized Shwartzman reaction (GSR) was induced by priming and challenged by i.v. injection of LPS and local Shwartzman reaction (LSR) was primed by intradermal injection of LPS and challenged by i.v. injection of LPS. Histological examination of the GSR animals showed, extensive thrombi accumulation in renal tubules and bilateral cortical necrosis of kidney in 8 out of 10 rabbits but none in the FXIII-DR. Fibrinogen levels were elevated to 3 approximately 4 fold at 24 h and lowered at 48 h whereas a steady rise was seen in the FXIII-DR. FDP levels in GSR animals were significantly elevated at 24 h and further increased at 48 h but only slightly elevated in the FXIII-DR. Examination of the LSR tissues after 48 h showed an acute onset of progressive cutaneous vascular thrombosis, purpura, and secondary hemorrhagic necrosis whereas neither fibrin deposit nor necrosis of tissue were detected in FXIII-DR despite of an early edema formation. Fibrinogen levels were also increased two fold at 24 h but returned to basal levels at 48 h in control LSR animals but not affected at all in FXIII-DR. These results suggest that during the severe inflammatory conditions such as sepsis, the fibrinolytic system is functionally sufficient to dissipate the pathogenic accumulation of disseminated intravascular clots and exudated fibrin clots if those clots were prevented from getting crosslinked in plasma.
Asunto(s)
Coagulación Intravascular Diseminada/complicaciones , Factor XIII/farmacología , Enfermedades Renales/prevención & control , Animales , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/aislamiento & purificación , Anticuerpos Monoclonales/farmacología , Modelos Animales de Enfermedad , Coagulación Intravascular Diseminada/prevención & control , Factor XIII/inmunología , Deficiencia del Factor XIII/complicaciones , Deficiencia del Factor XIII/fisiopatología , Fibrina/metabolismo , Fibrinógeno/efectos de los fármacos , Riñón/efectos de los fármacos , Riñón/patología , Enfermedades Renales/etiología , Lipopolisacáridos/administración & dosificación , Lipopolisacáridos/farmacología , Necrosis , Plasminógeno/efectos de los fármacos , Conejos , Sepsis , Fenómeno de Shwartzman/sangre , Fenómeno de Shwartzman/inducido químicamente , Piel/efectos de los fármacos , Piel/patología , Enfermedades de la Piel/etiología , Enfermedades de la Piel/prevención & controlRESUMEN
Adherence and aggregation of leukocytes within the vessels of a prepared skin site has been shown to be essential for the pathogenesis of the local Shwartzman reaction (LSR) (Argenbright and Barton: J Clin Invest 89: 259, 1992). We have now performed experiments in rabbits to evaluate whether coagulation within the vessels of a prepared site is a second requirement for the reaction. Skin sites were prepared by an intradermal injection of endotoxin 24 hours before a provoking intravenous injection of endotoxin. Thirteen control rabbits all developed the LSR. Seven of 12 rabbits given warfarin to achieve anticoagulation approximating that used therapeutically in humans before the provoking injection were protected against the LSR (p = 0.003). Five of nine rabbits given anti-rabbit factor X IgG before the provoking injection to yield mean values in individual rabbits of between 7% and 18% plasma factor X activity were protected against the LSR (p = 0.009). Six of 11 rabbits given anti-rabbit factor VII IgG before the provoking injection to yield mean values in individual rabbits of between < 0.5% and 2.2% were protected against the LSR (p = 0.007). Four rabbits failed to develop the LSR at an endotoxin-prepared skin site when an infusion of tissue factor (TF) causing substantial intravascular coagulation was substituted for a provoking injection of endotoxin. It would appear that two events are required for the pathogenesis of the LSR provoked by endotoxin: formation of aggregated masses of WBC in the prepared skin vessels and deposition of fibrin due to TF-initiated coagulation.
Asunto(s)
Coagulación Sanguínea/fisiología , Fenómeno de Shwartzman/sangre , Tromboplastina/fisiología , Animales , Coagulación Sanguínea/efectos de los fármacos , Pruebas de Coagulación Sanguínea , Agregación Celular , Endotoxinas/administración & dosificación , Endotoxinas/toxicidad , Factor VII/fisiología , Factor X/fisiología , Femenino , Fibrina/metabolismo , Inyecciones Intradérmicas , Inyecciones Intravenosas , Leucocitos/fisiología , Conejos , Fenómeno de Shwartzman/prevención & control , Tromboplastina/farmacología , Warfarina/farmacologíaRESUMEN
The involvement of cytokines in the pathogenesis of a generalized, Shwartzman-like lethal inflammatory response to bacterial lipopolysaccharides (LPS) was studied by testing the ability of cytokines or neutralizing anticytokine antibodies to modify the course of the syndrome. The reaction was elicitable in non-SPF NMRI mice by two consecutive injections of S. marcescens LPS: a first injection in the footpad, followed after 24 h by an intravenous dose; the size and route of the preparatory LPS dose were found to be critical. Treatment with mAbs against IFN-gamma was found to completely prevent the reaction. Treatment with IFN-gamma on the other hand, rendered the mice more sensitive to elicitation of the reaction. In contrast, systemic administration of IFN-alpha/beta exerted a desensitizing effect. The role of endogenous cytokines in the pathogenesis of this generalized Shwartzman reaction was also documented by a study of the cytokine levels in the serum of the mice. In comparisons between mice given lethal and nonlethal induction schedules, a good correlation was found between mortality rates and height of IFN or TNF levels, but no correlation was seen with IL-6 levels. Also, in mice that were protected by anti-IFN-gamma antibody, serum IFN and TNF were undetectable, whereas IL-6 levels were as high as in unprotected mice. These data provide evidence that among the cytokines that govern the inflammatory response to LPS, endogenous IFN-gamma occupies a key position. These findings therefore also open perspectives for clinical application of IFN-gamma antagonists.
Asunto(s)
Interferón gamma/fisiología , Lipopolisacáridos/farmacología , Fenómeno de Shwartzman/etiología , Animales , Anticuerpos Monoclonales , Factores Biológicos/sangre , Citocinas , Relación Dosis-Respuesta Inmunológica , Femenino , Interferón gamma/inmunología , Interferón gamma/farmacología , Ratones , Ratones Endogámicos , Premedicación , Proteínas Recombinantes , Fenómeno de Shwartzman/sangreRESUMEN
Pertussis toxin, and also cholera toxin are capable of inhibiting the effects of LPS in the elicitation of the generalized Schwartzman reaction. This is a potentially lethal generalized thrombo-haemorrhagic hypersensitivity and inflammatory-type response that occurs after two consecutive injections of LPS. The two exotoxins furnish significant protection against the lethal outcome of this reaction. It is known that the acute haematological and haemodynamic changes are accompanied by alterations in the levels of various endogenous mediators: glucocorticoid hormones, prostaglandins, arachidonic acid metabolites, cytokines and proteases. In vitro effects of LPS on murine leukocyte cell lines can be antagonized by pertussis toxin, implicating a Gi-like regulatory protein in the mediation of these effects. Experiments designed to study the involvement of particular second messenger systems (cAMP and phosphatidylinositol) used by LPS in vivo, revealed that the protective effects conferred by these exotoxins are associated with the antagonization of alterations caused by LPS. No correlation was found between the levels of IL-6 and the mortality rate in this experimental mouse model. The results indicate that G proteins play a role in the generation of the Schwartzman reaction and open a new approach for pharmacological intervention in endotoxemia and in clinical settings with Gram-negative sepsis.
Asunto(s)
Toxina del Cólera/farmacología , Lipopolisacáridos/farmacología , Toxina del Pertussis , Sistemas de Mensajero Secundario/efectos de los fármacos , Fenómeno de Shwartzman/prevención & control , Factores de Virulencia de Bordetella/farmacología , Animales , AMP Cíclico/sangre , Femenino , Interleucina-6/metabolismo , Ratones , Fosfatidilinositoles/metabolismo , Fenómeno de Shwartzman/sangre , Fenómeno de Shwartzman/inducido químicamenteRESUMEN
Dynamics of blood coagulation and morphological changes after the intravenous administration of Salmonella typhimurium endotoxin is studied experimentally in Chinchilla rabbits. The stages of blood coagulation are established characteristic for the above syndrome. The signs of the developing blood stasiopathy with the domination of vascular wall damage and thrombocyte aggregation are observed. No considerable consumption of the blood coagulation factors is found. It is concluded that a leading role in the pathogenesis of the endotoxin shock microcirculatory disturbances belongs to the vascular damage and aggregation thrombocytopenia and not to the coagulopathy consumption.
Asunto(s)
Coagulación Intravascular Diseminada/patología , Choque Séptico/patología , Animales , Coagulación Intravascular Diseminada/sangre , Coagulación Intravascular Diseminada/complicaciones , Endotoxinas/toxicidad , Hemostasis , Microscopía Electrónica , Conejos , Salmonella typhimurium , Choque Séptico/sangre , Choque Séptico/etiología , Fenómeno de Shwartzman/sangre , Fenómeno de Shwartzman/complicaciones , Fenómeno de Shwartzman/patología , Factores de TiempoRESUMEN
6-Sulfanilamidoindazole (6-SAI) is a sulfonamide that induces inflammation in the ankles and hind paws of older rats and sensitizes the animals to the lethal actions of endotoxin. Sensitization is associated with reductions in plasma glucose concentration but not changes in phagocytic function of the RES or increases in lysosomal or hepatic enzymes. Death in 6-SAI-pretreated but not control rats was associated with fibrin deposition in the glomerular capillaries (generalized Shwartzman reaction) and inflamed paws. Endotoxin shock in both 6-SAI-pretreated and control rats was associated with increases in activities of lysosomal and hepatic enzymes and hypoglycemia. Methylprednisolone but not desoxycorticosterone pretreatment protected 6-SAI-fed rats against endotoxin lethality and the generalized Shwartzman reaction and maintained the plasma glucose concentration but did not prevent loss of lysosomal integrity. Simultaneous administrations of small doses of phenylbutazone with 6-SAI suppressed inflammation but did not protect against endotoxin lethality or the generalized Shwartzman reaction.
Asunto(s)
Endotoxinas/toxicidad , Sulfanilamidas/farmacología , Fosfatasa Ácida/sangre , Alanina Transaminasa , Animales , Glucemia/análisis , Desoxicorticosterona/farmacología , Glucuronidasa/sangre , Hipoglucemia/fisiopatología , Inflamación/inducido químicamente , Inflamación/enzimología , Inflamación/fisiopatología , Masculino , Metilprednisolona/farmacología , Sistema Mononuclear Fagocítico/fisiopatología , Fagocitosis , Fenilbutazona/farmacología , Ratas , Ratas Endogámicas , Fenómeno de Shwartzman/sangre , Fenómeno de Shwartzman/fisiopatologíaRESUMEN
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.
Asunto(s)
Adenosina Difosfato/farmacología , Coagulación Sanguínea/efectos de los fármacos , Coagulación Intravascular Diseminada/sangre , Norepinefrina/farmacología , Trombina/farmacología , Trombosis/etiología , Adenosina Trifosfato/farmacología , Ácido Aminocaproico/farmacología , Animales , Aspirina/farmacología , Pruebas de Coagulación Sanguínea , Conejos , Fenómeno de Shwartzman/sangre , Trombosis/sangreRESUMEN
Schwartzman's phenomena, namely local and generalized reactions (SLR and SGR) were reproduced in two groups of rabbits weighing 1.5-2.5 kg. Use was made of endotoxin S. typhimurium obtained by the method of Bowen. Before endotoxin injection half of the animals of each group were given indomethacin (10 mg/kg). The coagulograms and thromboelastograms were examined after each endotoxin injection. Light and electron microscopy were used to study the animals' kidneys. Animals with the SLR and SGR demonstrated marked changes in the coagulogram and thromboelastogram characteristic of the development of the disseminated intravascular blood coagulation syndrome (DIC-syndrome). Animals' kidneys, particularly those in SGR, manifested gross structural and ultrastructural disorders, pronounced changes in microcirculation. Administration of indomethacin prevented the development of the DIC-syndrome. Besides, microscopic examination of the kidneys did not show fibrin release to the microcirculatory bloodstream. The data obtained indicate that the changes in hemostasis occurring in the SLR and SGR and microcirculatory disorders in the kidneys are linked with a dramatic intensification of prostaglandin synthesis, that develops in response to endotoxin injection.
Asunto(s)
Hemostasis , Prostaglandinas/fisiología , Fenómeno de Shwartzman/sangre , Animales , Riñón/irrigación sanguínea , Microcirculación/ultraestructura , Prostaglandinas/biosíntesis , Conejos , Salmonella typhimurium , Choque Séptico/sangre , Choque Séptico/patología , Fenómeno de Shwartzman/patología , TromboelastografíaAsunto(s)
Coagulación Intravascular Diseminada/diagnóstico , Animales , Complejo Antígeno-Anticuerpo/fisiología , Factores de Coagulación Sanguínea/análisis , Pruebas de Coagulación Sanguínea , Plaquetas/metabolismo , Plaquetas/fisiología , Cromatografía en Gel , Coagulación Intravascular Diseminada/sangre , Coagulación Intravascular Diseminada/fisiopatología , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Fibrinolisina/metabolismo , Fibrinopéptido A/análisis , Fibrinopéptido B/análisis , Humanos , Tiempo de Tromboplastina Parcial , Péptido Hidrolasas , Recuento de Plaquetas , Tiempo de Protrombina , Conejos , Fenómeno de Shwartzman/sangre , Trombina/metabolismo , Trombina/farmacología , Tromboplastina/fisiologíaRESUMEN
Several antiplatelet drugs (aspirin, sulfinpyrazone, hydroxychloroquine, dipyridamole, BL-3459, pyridinolcarbamate) were assayed for their ability to prevent the generalized Shwartzman reaction initiated by endotoxin in the pregnant rat, and compared to glucocorticoids (dexamethasone, hydrocortisone). The drugs were administered in a single large dose a few hours before provocation of the reaction. In opposition to glucocorticoids and beside BL-3459 which interfere with other mechanisms involved in the phenomenon, the tested inhibitors of platelet aggregation were found incapable of preventing or reducing the severity of the Shwartzman reaction.
Asunto(s)
Plaquetas/efectos de los fármacos , Preñez , Fenómeno de Shwartzman/tratamiento farmacológico , Animales , Femenino , Glucocorticoides/farmacología , Recuento de Plaquetas , Embarazo , Ratas , Fenómeno de Shwartzman/sangre , Fenómeno de Shwartzman/patologíaAsunto(s)
Viscosidad Sanguínea , Fenómeno de Shwartzman/sangre , Animales , Chinchilla , Femenino , Masculino , ConejosAsunto(s)
Ancrod/farmacología , Coagulación Intravascular Diseminada/patología , Venenos Elapídicos/farmacología , Riñón/patología , Fenómeno de Shwartzman/patología , Animales , Recuento de Células Sanguíneas , Coagulación Sanguínea , Factores de Coagulación Sanguínea , Plaquetas , Proteínas del Sistema Complemento , Coagulación Intravascular Diseminada/sangre , Coagulación Intravascular Diseminada/inducido químicamente , Fibrinógeno , Masculino , Polianetolsulfonato , Ratas , Fenómeno de Shwartzman/sangreRESUMEN
Intradermal injection of haptoglobin-hemoglobin (Hp-Hb) complex followed by intravenous injection of prostaglandin (PG) F2a or E2 produced a local Shwartzman-like phenomenon (LSLP) in rabbits, whereas PGE1 has no provoking action. Intradermal injection of hemoglobin or erythrocytes also produced LSLP when provoked with endotoxin or PGF2alpha. The provoking action of endotoxin in the local shwartzman reaction may not be entirely mediated through PGs.
Asunto(s)
Haptoglobinas/farmacología , Hemoglobinas/farmacología , Prostaglandinas/farmacología , Fenómeno de Shwartzman/sangre , Animales , Endotoxinas/farmacología , Indometacina/farmacología , Inyecciones Intradérmicas , Prostaglandinas E/farmacología , Prostaglandinas F/farmacología , ConejosRESUMEN
The conventional local Shwartzman reaction (LSR) did not occur in rabbits whose plasma haptoglobin (Hp) was lowered by treatment with carbon tetrachloride, nor in animals in whom Hp was elevated after treatment with turpentine, or PGE2 or endotoxin. The possible mechanisms of such inhibition of the LSR are discussed.
Asunto(s)
Tetracloruro de Carbono/farmacología , Fenómeno de Shwartzman/sangre , Trementina/farmacología , Animales , Endotoxinas/farmacología , Haptoglobinas , ConejosRESUMEN
A fibrin slide test was utilized to study cutaneous vascular plasminogen activator activity in normal rabbit, rat, monkey, and human skin and in rabbit skin following development of the local Shwartzman reaction and after substituting epsilon-aminocaproic acid for the preparatory injection of endotoxin in the local Shwartzman reaction. Cutaneous vascular plasminogen activator activity was also studied in rats after attempted induction of the local Shwartzman reaction following inhibition of fibrinolysis with epsilon-aminocaproic acid and/or pregnancy. Plasminogen activator activity was detected in vessels of normal rat, monkey, and human skin but was absent in skin from normal rabbits and rabbits with the local Shwartzman reaction. Intradermal injection of epsilon-aminocaproic acid failed to prepare for the local Shwartzman reaction. In the rat, which has greater cutaneous vascular plasminogen activator activity than the rabbit, inhibition of vascular activator with epsilon-aminocaproic acid and/or pregnancy failed to prepare for the local Shwartzman reaction. These studies indicate that although the markedly diminished level of cutaneous vascular plasminogen activator in the rabbit may be important in the pathogenesis of the local Shwatzman reaction, factors other than inhibition of fibrinolysis are also necessary for preparation of the reaction.