RESUMEN
Pregnancy toxemia (PT) is considered one of the most common metabolic diseases with high impact on the production of small ruminants. The objective of this study was investigate possible myocardial damage in goats affected with PT by the determination of serum myocardial biomarkers CK-MB and cTnI. A total of 44 goats affected with PT, and 10 apparently healthy goats (control group or CG) were used in the study. In goats with PT, the serum concentrations of cTnI (0.43 ng/mL) were significantly higher than that in CG goats (0.06 ng/mL). Although CK-MB showed no significant difference, it was approximately three times higher in animals with PT. The serum concentrations of insulin were significantly lower in PT goats (5.03 ppmol/L) compared to CG goats (10.66 pmol/L). The serum concentrations of cortisol in PT goats (155.41 nmol/L) were significantly higher than that in CG goats (36.58 nmol/L). Results of this study indicate that a clinically significant myocardial damage might occur in goats affected with PT leading to significant elevations in values of cTnI and CK-MB. Therefore, these parameters could be used as a potential prognostic indicator in goats affected with this important disease.
Asunto(s)
Biomarcadores/metabolismo , Enfermedades de las Cabras/metabolismo , Miocardio/metabolismo , Preeclampsia/veterinaria , Animales , Femenino , Cabras , Preeclampsia/metabolismo , Embarazo , Toxemia/metabolismo , Toxemia/veterinariaRESUMEN
In 76 injured persons with deep and superficial burns, having area from 3 to 65% of the total body surface and ageing 5-16 yrs old, there was investigated the impact of early surgical treatment on the metabolic intoxication severity in accordance to content of the oxidatively modified proteins carbonyl groups in the blood serum, and of a ceruloplasmin, what was considered as integral express-index of the organism antioxidant system state. Changes of these indices in ambustial disease of middle severity have witnessed a sufficiently compensated reaction of organism: of severe and extremely severe one--there were noted a deficiency of the organism antioxidant defense; and in stages of toxemia and septicotoxemia--attrition of the organism oxidant reserves and danger of the septic complications occurrence. Conduction of early surgical intervention have guaranteed maintenance of a ceruloplasmin content in stages of toxemia and septicotoxemia on the level of healthy persons, relief of the ambustial disease course, absence of critical metabolic intoxication and carbonyl stress, reduction of the septic complications rate in 1.5 times.
Asunto(s)
Quemaduras/cirugía , Procedimientos Quirúrgicos Dermatologicos , Trasplante de Piel , Traumatismos de los Tejidos Blandos/cirugía , Toxemia/cirugía , Adolescente , Quemaduras/metabolismo , Quemaduras/patología , Ceruloplasmina/metabolismo , Niño , Preescolar , Femenino , Humanos , Masculino , Carbonilación Proteica , Índice de Severidad de la Enfermedad , Piel/metabolismo , Piel/patología , Piel Artificial , Traumatismos de los Tejidos Blandos/complicaciones , Traumatismos de los Tejidos Blandos/metabolismo , Traumatismos de los Tejidos Blandos/patología , Toxemia/complicaciones , Toxemia/metabolismo , Toxemia/patología , Trasplante AutólogoRESUMEN
The study is based on the analysis of the conservative and surgical treatment of 123 patients with the "sterile phase" of pancreonecrosis, completed by the evaluation of biochemical indexes of the endogenous intoxication. The achieved results specify the important role of the independent inflammation predictors in a complex estimation of the severity prognosis and the complication possibility after the operative treatment of the acute destructive pancreatitis.
Asunto(s)
Drenaje , Páncreas/cirugía , Pancreatectomía , Seudoquiste Pancreático/cirugía , Pancreatitis Aguda Necrotizante , Toxemia , APACHE , Adulto , Drenaje/efectos adversos , Drenaje/métodos , Femenino , Humanos , Inflamación/etiología , Inflamación/metabolismo , Inflamación/patología , Masculino , Metabolismo , Necrosis/etiología , Necrosis/metabolismo , Necrosis/patología , Oligopéptidos/metabolismo , Páncreas/patología , Páncreas/fisiopatología , Pancreatectomía/efectos adversos , Pancreatectomía/métodos , Seudoquiste Pancreático/etiología , Pancreatitis Aguda Necrotizante/complicaciones , Pancreatitis Aguda Necrotizante/metabolismo , Pancreatitis Aguda Necrotizante/fisiopatología , Pronóstico , Estudios Retrospectivos , Toxemia/etiología , Toxemia/metabolismo , Resultado del TratamientoRESUMEN
Prophylactic dietary intake of synthetic ubiquinone-10, succinic acid, or mixture of these substances prevented disturbances in aggregation and electrophoretic mobility of erythrocytes and inhibited lipid peroxidation in cells of rats with experimental epinephrine-induced toxemia.
Asunto(s)
Epinefrina/toxicidad , Eritrocitos/efectos de los fármacos , Ácido Succínico/farmacología , Toxemia/sangre , Ubiquinona/farmacología , Animales , Agregación Eritrocitaria/efectos de los fármacos , Eritrocitos/metabolismo , Femenino , Hipoxia , Peroxidación de Lípido , Modelos Biológicos , Ratas , Toxemia/metabolismoRESUMEN
The transcription factor NF-kappaB is an important regulator of homeostatic growth and inflammation. Although gene-targeting studies have revealed important roles for NF-kappaB, they have been complicated by component redundancy and lethal phenotypes. To examine the role of NF-kappaB in endothelial tissues, Tie2 promoter/enhancer-IkappaBalpha(S32A/S36A) transgenic mice were generated. These mice grew normally but exhibited enhanced sensitivity to LPS-induced toxemia, notable for an increase in vascular permeability and apoptosis. Moreover, B16-BL6 tumors grew significantly more aggressively in transgenic mice, underscoring a new role for NF-kappaB in the homeostatic response to cancer. Tumor vasculature in transgenic mice was extensive and disorganized. This correlated with a marked loss in tight junction formation and suggests that NF-kappaB plays an important role in the maintenance of vascular integrity and response to stress.
Asunto(s)
Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Lipopolisacáridos/farmacología , FN-kappa B/metabolismo , Neoplasias/metabolismo , Toxemia/metabolismo , Animales , Línea Celular , Transformación Celular Neoplásica , Células Endoteliales/ultraestructura , Predisposición Genética a la Enfermedad , Humanos , Quinasa I-kappa B/genética , Quinasa I-kappa B/metabolismo , Ratones , Ratones Transgénicos , Microscopía Electrónica , Permeabilidad/efectos de los fármacos , Sepsis/inducido químicamente , Sepsis/metabolismo , Sepsis/patología , Estrés Fisiológico/inducido químicamente , Estrés Fisiológico/genética , Estrés Fisiológico/metabolismo , Estrés Fisiológico/patología , Toxemia/genética , Toxemia/patología , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Lysinuric protein intolerance (LPI) is an autosomal recessive transport disorder of the dibasic amino acids. The defect leads to deficiency of lysine, arginine, and ornithine and, secondarily, to a functional disorder of the urea cycle. Transient postprandial hyperammonemia and subsequent persistent protein aversion, linked with several other biochemical and clinical characteristics of the disease, suggest an increased risk for maternal and fetal complications during pregnancy and delivery. Our unique material on the outcomes of 18 pregnancies of 9 Finnish mothers with LPI and the follow-up of their 19 children shows that maternal LPI is truly associated with increased risk of anemia, toxemia, and intrauterine growth retardation during pregnancy and bleeding complications during delivery. Successful pregnancies and deliveries can still be achieved with careful follow-up of blood pressure and laboratory values. The children of the mothers with LPI generally develop normally. Special care of maternal protein nutrition and control of ammonemia, anemia, and toxemia during pregnancy are essential. We propose centralization of deliveries to obstetric units with capability to deal with bleeding complications and rare inborn errors of metabolism.
Asunto(s)
Trastornos Innatos del Transporte de Aminoácidos/genética , Trastornos Innatos del Transporte de Aminoácidos/metabolismo , Aminoácidos Diaminos/metabolismo , Complicaciones del Embarazo/metabolismo , Adulto , Trastornos Innatos del Transporte de Aminoácidos/patología , Aminoácidos Diaminos/sangre , Aminoácidos Diaminos/orina , Presión Sanguínea/fisiología , Femenino , Hemoglobinas/metabolismo , Humanos , Recién Nacido , Ácido Orótico/orina , Embarazo , Complicaciones del Embarazo/genética , Complicaciones del Embarazo/patología , Toxemia/metabolismo , Urea/metabolismoRESUMEN
Diarrhea is a common manifestation of sepsis. We hypothesized that endotoxin may impair colonic absorption of water and electrolytes, an effect which may be related to altered liquid transit in the colon. Five dogs underwent construction of 50-cm colonic Thiry-Vella fistulas (TVF). Following recovery, absorption studies were performed by perfusing the TVF with an isotonic solution at 2.9 ml/min containing polyethylene glycol (5 g/L). Fasting and postprandial colonic absorption of water, electrolytes, and glucose were determined. Liquid transit was assessed by bolus of a nonabsorbable marker (PSP) instilled into the proximal end of the TVF. Following completion of the baseline studies, each dog was given a single dose of Escherichia coli lipopolysaccharide 200 micrograms/kg i.v. and the studies were repeated daily for the next 3 days. Following endotoxin bolus, colonic absorption of water and sodium were decreased during fasting, while postprandial colonic absorption of water was also decreased. Colonic absorption of water and sodium returned to baseline values on postendotoxin day 2. Colonic secretion of potassium was decreased on postendotoxin days 1 and 3 in both the fasting and the fed periods. Fasting and postprandial liquid transit was also rapid on postendotoxin day 1, which correlated with the decreased absorption seen on that day. Liquid transit returned to baseline values on postendotoxin day 2. We conclude that endotoxin temporarily impairs postprandial colonic absorption, which may be due to the rapid liquid transit that occurs. These effects may contribute to the diarrhea seen during and after septic episodes.
Asunto(s)
Colon/efectos de los fármacos , Colon/fisiología , Absorción Intestinal/efectos de los fármacos , Lipopolisacáridos/toxicidad , Sodio/farmacocinética , Agua/metabolismo , Animales , Cateterismo , Colon/cirugía , Diarrea/etiología , Diarrea/metabolismo , Perros , Ingestión de Alimentos , Ayuno , Inyecciones Intravenosas , Transporte Iónico/efectos de los fármacos , Lipopolisacáridos/administración & dosificación , Potasio/farmacocinética , Sepsis/complicaciones , Sepsis/metabolismo , Toxemia/complicaciones , Toxemia/metabolismoRESUMEN
The hepatic asialoglycoprotein receptor is responsible for rapid clearance of desiaylated glycoproteins from the circulation by receptor-mediated endocytosis. Previous in vitro studies in hepatocyte preparations from rats subjected to partial hepatectomy (PH) of 70% to stimulate hepatic regeneration showed decreased asialoglycoprotein (ASGP) receptor binding. We used an ASGP receptor-targeted hepatic magnetic resonance imaging (MRI) agent, BMS 180550, to demonstrate similar changes in receptor biology in vivo. BMS 180550 is an arabinogalactan-coated ultrasmall superparamagnetic iron oxide preparation. Arabinogalactan is a ligand for the ASGP receptor and, thereby, targets the contrast agent exclusively to hepatocytes. Hepatic uptake of BMS 180550 was assessed by sequential precontrast and post-contrast MRI in rats subjected to PH of 70%. In regenerating liver 1 and 3 days after PH, the maximum decrease in hepatic signal intensity (62.2% +/- 6.1 and 59.4% +/- 3.8, respectively) was significantly less than the maximum decrease seen in sham-operated animals at 1 and 3 days postsurgery (39.5% +/- 2.5 and 44% +/- 1.0, respectively). The time necessary to reach 80% of the maximum decrease in hepatic signal intensity, (t80), was less than 2 minutes in control rats and increased to 7.5 +/- 1.3 min and 11.0 +/- 2.3 minutes at 1 and 3 days post-PH, respectively. By 7 days post-PH, contrast-enhanced MRI no longer detected a difference in regenerating liver. Because BMS 180550 is taken up exclusively by the liver, clearance of the agent from the blood was used as a measure of hepatic clearance. Concentration-time curves constructed by measuring changes in blood T2 after an intravenous dose of BMS 180550 were used to determine clearance of the agent. Blood clearance of BMS 180550 in normal liver (15.4 +/- 1.08 mL/min) obeyed first-order kinetics and did not vary over the dose range tested (10 to 100 micromol/L/kg iron). One, 3, 7, and 14 days post-PH, clearance varied with dose, suggesting ASGP receptor saturation. As regeneration proceeded, the dose of contrast agent needed to cause a deviation from first-order kinetics increased, suggesting gradual recovery of ASGP receptor function. Hepatic relaxation was determined by in vitro spectroscopy 60 minutes after administration of graded doses of BMS 180550 and showed dose-dependent increases in relaxation. Kinetic analysis at 1 day post-PH demonstrated a decrease in the apparent k(m) and the maximum response, R(max), suggesting a decrease in the number of functional asialoglycoprotein receptors with concomitant increase in receptor affinity. Systemic endotoxemia, which normally accompanies hepatic regeneration induced by PH, also decreased clearance of BMS 180550 and slowed hepatic uptake of the contrast agent. Altered BMS 180550 pharmacokinetics in endotoxin-treated rats was enhanced by prior administration of small doses of competing ligand. Our studies document the value of BMS 180550 in following changes in ASGP function that accompany PH or systemic endotoxemia. This agent may be useful in assessing the degree of hepatic regeneration in patients with clinical liver disease.
Asunto(s)
Medios de Contraste/farmacocinética , Galactanos/farmacocinética , Hierro/farmacocinética , Regeneración Hepática/fisiología , Hígado/metabolismo , Óxidos/farmacocinética , Receptores de Superficie Celular/metabolismo , Toxemia/metabolismo , Animales , Receptor de Asialoglicoproteína , Transporte Biológico Activo , Endotoxinas/toxicidad , Galactanos/sangre , Hepatectomía , Hierro/sangre , Cinética , Imagen por Resonancia Magnética , Masculino , Tasa de Depuración Metabólica , Óxidos/sangre , Ratas , Ratas Sprague-DawleyRESUMEN
Dienoic eicosanoids derived from phospholipid arachidonic acid (AA) in lung and liver macrophages promote leukosequestration, thrombosis, and tissue injury. Current enteral diets (diet A) are enriched with linoleic acid (LA), a precursor of AA. Novel diets low in LA and containing eicosapentaenoic acid (EPA) and gamma-linolenic acid (GLA) foster formation of less inflammatory eicosanoids. The study objective was to assess the rapidity and extent of LA and AA displacement in vivo from alveolar macrophage (AM phi), lung, and liver Kupffer and endothelial (KE) cell phospholipids in rats fed enterally with diets enriched with 5.3% (by wt) EPA and either 1.2% or 4.6% GLA (diets B and C, respectively). After surgical placement of catheters, the rats were fed enterally and co-infused intravenously with either endotoxin or vehicle continuously for 3 or 6 d. Rats given either diet B or C had significantly lower (P < 0.01) relative percentages of AA and LA within the AM phi, lung, and KE cell phospholipids, and concomitantly higher percentages of EPA compared with rats infused with diet A after 3 d of enteral feeding irrespective of endotoxin co-infusion. Incorporation of dihomo-gamma-linolenic acid (DHGLA), the metabolite of GLA, into lung and KE phospholipids was significant in rats given diet C. Most of the changes in fatty acid composition occurred by day 3. The polyunsaturated fatty acid composition of AM phi, lung, and KE cell phospholipids can be rapidly modified by continuous short-term enteral feeding with EPA- and GLA-enriched diets irrespective of concurrent endotoxemia.
Asunto(s)
Ácido Eicosapentaenoico/administración & dosificación , Ácidos Grasos Insaturados/metabolismo , Hígado/citología , Pulmón/citología , Macrófagos/metabolismo , Toxemia/metabolismo , Ácido gammalinolénico/administración & dosificación , Animales , Cromatografía en Capa Delgada , Endotoxinas/administración & dosificación , Nutrición Enteral , Células Epitelioides/metabolismo , Escherichia coli , Infusiones Intravenosas , Macrófagos del Hígado/metabolismo , Macrófagos Alveolares/metabolismo , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-DawleyRESUMEN
Short-term preexposure of mononuclear cells to epinephrine inhibits LPS-induced production of TNF, whereas preexposure for 24 h results in increased TNF production. To assess the effects of epinephrine infusions of varying duration on in vivo responses to LPS, the following experiments were performed: (a) Blood obtained from eight subjects at 4-24 h after the start of a 24-h infusion of epinephrine (30 ng/kg per min) produced less TNF after ex vivo stimulation with LPS compared with blood drawn before the start of the infusion, and (b) 17 healthy men who were receiving a continuous infusion of epinephrine (30 ng/kg per min) started either 3 h (EPI-3; n = 5) or 24 h (EPI-24; n = 6) were studied after intravenous injection of LPS (2 ng/kg, lot EC-5). EPI-3 inhibited LPS-induced in vivo TNF appearance and also increased IL-10 release (both P < 0.005 versus LPS), whereas EPI-24 only attenuated TNF secretion (P = 0.05). In separate in vitro experiments in whole blood, epinephrine increased LPS-induced IL-10 release by a combined effect on alpha and beta adrenergic receptors. Further, in LPS-stimulated blood, the increase on IL-10 levels caused by epinephrine only marginally contributed to concurrent inhibition of TNF production. Epinephrine, either endogenously produced or administered as a component of sepsis treatment, may have a net antiinflammatory effect on the cytokine network early in the course of systemic infection.
Asunto(s)
Endotoxinas , Epinefrina/farmacología , Interleucina-10/biosíntesis , Toxemia/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Humanos , Infusiones Intravenosas , Masculino , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos beta/metabolismoAsunto(s)
Quimiocinas CXC , Péptidos y Proteínas de Señalización Intercelular , Hígado/metabolismo , Sepsis/metabolismo , Toxemia/metabolismo , Animales , Células Cultivadas , Factores Quimiotácticos/biosíntesis , Endotoxinas/toxicidad , Glutatión/metabolismo , Sustancias de Crecimiento/biosíntesis , Macrófagos del Hígado/metabolismo , Hígado/patología , Masculino , Neutrófilos/efectos de los fármacos , Neutrófilos/patología , Estrés Oxidativo , Ratas , Ratas Sprague-DawleyRESUMEN
OBJECTIVE: To evaluate the hypothesis that splanchnic ischemia and mucosal hypoxia are responsible for lipopolysaccharide-induced intramucosal acidosis in pigs. DESIGN: Prospective, randomized, unblinded study. SETTING: Surgical research laboratory at a large, university-affiliated medical center. SUBJECTS: Anesthetized, mechanically ventilated swine. INTERVENTIONS: Pigs were infused with lactated Ringer's solution (12 mL/kg/hr) and, starting at 30 mins, 25-mL boluses of dextran-70 (maximum 15 mL/kg/hr) to maintain cardiac output at 90% to 110% of the baseline value for each pig. Ileal mucosal hydrogen ion concentration was measured tonometrically. A segment of distal ileum was exteriorized, opened, and placed on a platform to permit measurement of mucosal PO2, using an array of Clark-type microelectrodes and a computerized data acquisition and analysis system. Mucosal perfusion was measured using laser-Doppler flowmetry. The control group (n = 4) received no further interventions. Pigs in the lipopolysaccharide group (n = 6) were infused with 150 micrograms/kg of Escherichia coli lipopolysaccharide over 60 mins. To assess the effect of mucosal acidosis on mucosal PO2 in nonendotoxemic animals, intramucosal hydrogen ion concentration, mucosal PO2, and mucosal perfusion were measured in pigs rendered hypercarbic through deliberate hypoventilation (hypercarbia group; n = 4). MEASUREMENTS AND MAIN RESULTS: Infusion of lipopolysaccharide resulted in a significant increase in intramucosal hydrogen ion concentration. However, in the lipopolysaccharide group, mucosal perfusion did not change significantly and mucosal PO2 increased significantly. In the hypercarbia group, hypercarbia was associated with significant increases in both intramucosal hydrogen ion concentration and mucosal PO2. CONCLUSIONS: Mucosal hypoxia is not responsible for lipopolysaccharide-induced mucosal acidosis in this normodynamic pig model of septic shock. A rightward shift of the oxyhemoglobin dissociation curve (the Bohr effect) can explain the increase in mucosal oxygenation observed in endotoxemic pigs.
Asunto(s)
Acidosis/etiología , Modelos Animales de Enfermedad , Endotoxinas/sangre , Hipoxia/complicaciones , Enfermedades del Íleon/etiología , Mucosa Intestinal/metabolismo , Choque Séptico/etiología , Toxemia/complicaciones , Acidosis/metabolismo , Animales , Escherichia coli , Concentración de Iones de Hidrógeno , Hipoxia/metabolismo , Enfermedades del Íleon/metabolismo , Lipopolisacáridos/administración & dosificación , Masculino , Consumo de Oxígeno , Presión Parcial , Estudios Prospectivos , Distribución Aleatoria , Choque Séptico/metabolismo , Porcinos , Toxemia/metabolismoRESUMEN
OBJECTIVES: This study was conducted to determine the role of gut-derived bacteria/endotoxin in the pathogenesis of the multiple-organ damage and mortality, the possible beneficial effect of recombinant bactericidal/permeability-increasing protein (rBPl21), and whether neutralizing endotoxemia by rBPl21 treatment influences tumor necrosis factor (TNF) formation in rats after hemorrhagic shock and resuscitation. SUMMARY BACKGROUND DATA: Hypovolemic shock might be associated with bacterial or endotoxin translocation as well as systemic sepsis. Similar to bactericidal/permeability-increasing (BPl) protein, rBPl21 has been found to bind endotoxin and inhibit TNF production. METHODS: A rat model of prolonged hemorrhagic shock (30 to 35 mm Hg for 180 min) followed by adequate resuscitation was employed. Recombinant bactericidal/permeability-increasing protein was administered at 5 mg/kg intravenously. The control group was treated similarly to the BPl group, but received thaumatin as a protein-control preparation in the same dose as rBPl21. RESULTS: Immediately after resuscitation (230 min), plasma endotoxin levels in the control group (61.0 +/- 16.3 pg/mL) were almost neutralized by rBPl21 treatment (13.8 +/- 4.8 pg/mL, p < 0.05). Plasma TNF levels were not significantly influenced by rBPl21 treatment. The 48-hour survival rate was 68.8% in the treatment group versus 37.5% in the control group (p = 0.08). Microscopic histopathologic examination revealed relatively minor damage to various organs in the treatment group. CONCLUSIONS: These data suggest that hemorrhagic shock may lead to bacterial/endotoxin translocation with concomitant TNF formation, endogenous endotoxemia may play an important role in the pathogenesis of multiple-organ failure after shock and trauma, TNF formation at an early stage might be related mainly to mechanisms other than Kupffer's cells activation via lipopolysaccharide, and rBPl21 might be a useful therapeutic agent against endogenous bacteria/endotoxin related disorders in severe hemorrhagic shock.
Asunto(s)
Proteínas Sanguíneas/uso terapéutico , Endotoxinas/farmacocinética , Escherichia coli/fisiología , Proteínas de la Membrana , Fragmentos de Péptidos/farmacología , Choque Hemorrágico/microbiología , Toxemia/terapia , Animales , Péptidos Catiónicos Antimicrobianos , Movimiento Celular , Masculino , Permeabilidad , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes/uso terapéutico , Choque Hemorrágico/metabolismo , Choque Hemorrágico/terapia , Toxemia/metabolismo , Toxemia/microbiología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
We examined the kinetics of tumor necrosis factor (TNF) production induced by Escherichia coli lipopolysaccharide (LPS) in relation to LPS tolerance and endotoxemic lesions of piglets. The plasma of piglets demonstrated cytotoxicity to TNF-sensitive L929 cells between 0.5 and 4 h after inoculation with 200 micrograms kg-1 of LPS. This cytotoxicity was neutralized by anti-bovine TNF serum. These piglets had disseminated intravascular coagulation (DIC) and meningoencephalitis. However, if piglets were first treated with three doses of 40 micrograms kg-1 of LPS, both TNF production and the occurrence of DIC were inhibited when 200 micrograms kg-1 of LPS was inoculated into these piglets. Repetitive inoculation with increasing doses of LPS induced fibrinoid vasculitis, meningoencephalitis and pneumonitis, while hemorrhage was minimal. A very low amount of TNF activity was detected from most of the samples of a piglet after repeated LPS inoculation. These results suggested that severity of the hemorrhagic and thrombotic lesions might relate to the amount of endogenous TNF activity, and that LPS tolerance might relate to inhibition of TNF production.
Asunto(s)
Escherichia coli , Lipopolisacáridos , Enfermedades de los Porcinos/metabolismo , Enfermedades de los Porcinos/patología , Toxemia/veterinaria , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Pruebas Inmunológicas de Citotoxicidad/veterinaria , Citotoxicidad Inmunológica/inmunología , Coagulación Intravascular Diseminada/metabolismo , Coagulación Intravascular Diseminada/patología , Coagulación Intravascular Diseminada/veterinaria , Femenino , Inyecciones Intravenosas/veterinaria , Riñón/patología , Lipopolisacáridos/toxicidad , Pulmón/patología , Enfermedades Pulmonares Intersticiales/metabolismo , Enfermedades Pulmonares Intersticiales/patología , Enfermedades Pulmonares Intersticiales/veterinaria , Masculino , Meningoencefalitis/metabolismo , Meningoencefalitis/patología , Meningoencefalitis/veterinaria , Médula Espinal/patología , Bazo/patología , Porcinos , Toxemia/metabolismo , Toxemia/patología , Vasculitis/metabolismo , Vasculitis/patología , Vasculitis/veterinariaRESUMEN
We used the intragastric feeding rat model for alcoholic liver disease to evaluate the relationship among intercellular adhesion molecule-1 (ICAM-1) expression, tumor necrosis factor-alpha (TNF-alpha), plasma endotoxin, and inflammatory changes in the liver. Rats were fed different dietary fats (saturated fat, corn oil, and fish oil) with ethanol; control rats were fed isocaloric amounts of dextrose instead of ethanol. At sacrifice the following were evaluated: liver pathologic changes, TNF-alpha mRNA by reverse transcription-PCR, plasma endotoxin, and ICAM-1 by immunohistochemistry and immunoblot analysis. Upregulation of ICAM-1 in endothelial lining cells in central and portal veins was observed in rats showing evidence of pathologic changes. Rats fed fish oil and ethanol, which exhibited the most severe inflammation, also showed hepatocyte ICAM-1 staining. The presence of ICAM-1 staining, in general, correlated with the level of TNF-alpha mRNA expression and plasma endotoxin levels. Upregulation of ICAM-1 in rats fed ethanol may contribute to the inflammatory changes seen in this model. The association between ICAM-1 upregulation and endotoxin and TNF-alpha mRNA suggests a role for these mediators in the inflammatory process in alcoholic liver injury.
Asunto(s)
Molécula 1 de Adhesión Intercelular/análisis , Hepatopatías Alcohólicas/metabolismo , ARN Mensajero/análisis , Toxemia/metabolismo , Factor de Necrosis Tumoral alfa/toxicidad , Alimentación Animal , Animales , Secuencia de Bases , Molécula 1 de Adhesión Intercelular/biosíntesis , Hígado/efectos de los fármacos , Hígado/patología , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/genética , Masculino , Datos de Secuencia Molecular , Ratas , Ratas Wistar , Toxemia/etiología , Toxemia/genética , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
Acute endotoxemia is associated with activation of hepatic macrophages and endothelial cells. These cells release a variety of inflammatory mediators that have been implicated in tissue injury. In the present studies, we analyzed the biochemical responses of these cells to platelet-activating factor (PAF), a lipid autacoid released during hepatic inflammatory responses. To induce acute endotoxemia, rats were injected intravenously with lipopolysaccharide (LPS). Using the calcium sensitive fluorescent indicator dye Indo-1, we found that PAF induced a rapid and transient increase in intracellular calcium in both hepatic macrophages and endothelial cells. Induction of acute endotoxemia resulted in an increase in the amount of calcium mobilized by both cell types. Although endothelial cells from control rats were less responsive to PAF than macrophages, these cells were more sensitive to in vivo endotoxin. PAF was also found to cause a rapid decrease in intracellular pH in hepatic macrophages that was quantified by fluorescence image analysis using the pH sensitive dye SNAFL-calcein. This decrease occurred more rapidly in macrophages from endotoxemic rats. In cells from both control and endotoxemic rats, the effects of PAF on intracellular pH were inhibited by the specific PAF antagonist triazolam. In contrast to hepatic macrophages, PAF had no effect on intracellular pH in endothelial cells from either control or endotoxemic rats. Ligand binding studies demonstrated that both hepatic macrophages and endothelial cells possess high affinity binding sites for PAF. Macrophages expressed 6- to 7-fold more binding sites/cell than endothelial cells and exhibited a higher Kd. Whereas treatment of rats with LPS had no effect on the Kd for PAF binding to macrophages or on the number of binding sites, a significant increase in both of these receptor characteristics was observed in endothelial cells. Taken together, the present data suggest that the biochemical responses of endothelial cells and macrophages to PAF are distinct. Furthermore, cellular activation induced by PAF in endothelial cells appears to be independent of changes in intracellular pH.
Asunto(s)
Endotoxinas/toxicidad , Hígado/citología , Hígado/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Factor de Activación Plaquetaria/farmacología , Receptores de Superficie Celular , Receptores Acoplados a Proteínas G , Toxemia/fisiopatología , Enfermedad Aguda , Animales , Calcio/metabolismo , Endotelio/citología , Endotelio/efectos de los fármacos , Endotelio/metabolismo , Endotoxinas/sangre , Concentración de Iones de Hidrógeno , Inflamación/inmunología , Hígado/patología , Activación de Macrófagos/efectos de los fármacos , Activación de Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Glicoproteínas de Membrana Plaquetaria/metabolismo , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Toxemia/inmunología , Toxemia/metabolismoAsunto(s)
Abdomen Agudo , Endotoxinas/sangre , Supuración , Toxemia/etiología , Enfermedad Aguda , Hipoxia de la Célula , Endotoxinas/metabolismo , Humanos , Hipoxia/metabolismo , Peroxidación de Lípido , Fosforilación , Supuración/enzimología , Supuración/metabolismo , Toxemia/enzimología , Toxemia/metabolismoRESUMEN
Since the 1930s and the discovery by von Euler of a vasoactive, lipid-soluble substance that he erroneously assumed was generated by the prostate gland and therefore should be called "prostaglandin," the family of prostaglandins has grown to some 90 substances. These lipid mediators are derived from arachidonic acid in the "arachidonic acid cascade." In 1976, while looking for the enzyme that generates the unstable prostanoid thromboxane A2 from arachidonic acid, Moncada and Vane discovered prostaglandin I2 and renamed it "prostacyclin." Prostacyclin is the main product of arachidonic acid in all vascular tissues tested to date and strongly vasodilates all vascular beds studied. It is also the most potent endogenous inhibitor of platelet aggregation yet discovered, both inhibiting aggregation and dispersing existing aggregates. It acts through activation of adenylate cyclase, leading to increased levels of cyclic adenosine monophosphate. It also appears to have a "cytoprotective" activity, as yet not completely understood. Its effects are short-lasting, disappearing within 30 minutes of cessation of infusion. A stable, freeze-dried preparation of prostacyclin (epoprostenol) is available for administration to humans, and several analogs with therapeutically desirable characteristics are currently being clinically tested and should become commercially available soon. Clinical application of prostacyclin is bedeviled by 2 characteristics: it is pharmacologically unstable, so care must be taken in its use, and the correct dosage regimens have not yet been established.