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PubMed2004

Endotoxin pretreatment modifies peristalsis and attenuates the antipropulsive action of adrenoceptor agonists in the guinea-pig small intestine.

The action of endotoxin to alter gastrointestinal motility in vivo may reflect a direct effect on the gut or result from vascular and other systemic manifestations of this sepsis model. Here we examined whether in vivo pretreatment of guinea-pigs with endotoxin modifies peristalsis in the isolated gut and influences the antipropulsive action of adrenoceptor agonists. Distension-induced peristalsis was recorded in fluid-perfused segments of the small intestine taken from animals pretreated intraperitoneally with endotoxin (1 mg kg(-1)Escherichia coli lipopolysaccharide) or vehicle 4 or 20 h before. Clonidine, adrenaline, noradrenaline, dopamine and dobutamine inhibited peristalsis with differential potency. Endotoxin pretreatment lowered the peristaltic pressure threshold and altered other parameters of baseline peristalsis in a time-related manner. The potency and efficacy of clonidine to inhibit peristalsis were markedly decreased after endotoxin administration, while the potency of the other test drugs was less attenuated. The antipropulsive action of clonidine in control segments was reduced by yohimbine and prazosin, whereas in segments from endotoxin-pretreated animals it was antagonized by yohimbine but not prazosin. We conclude that systemic endotoxin pretreatment of guinea-pigs modifies baseline peristalsis by an action on the gut and inhibits the antipropulsive action of adrenoceptor agonists through changes in adrenoceptor activity.

Adrenergic Agonists↗
PubMed1994

The redistribution of granulocytes following E. coli endotoxin induced sepsis.

Infusion of endotoxin elicits granulocytopenia followed by increased numbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocytes in the tissues following E. coli endotoxin induced sepsis. From 16 rabbits granulocytes were isolated, labelled with Indium and reinjected intravenously. Eight rabbits received an infusion of E. coli endotoxin 2 micrograms kg-1 while eight received isotonic saline. The redistribution of granulocytes was imaged with a gamma camera and calculated with a connected computer before and 2 and 6 hours after infusion of endotoxin or saline. Serum cortisol and interleukin-1 beta were measured. In another seven rabbits, respiratory burst activity and degranulation of granulocytes were measured prior to and from 5 min to 6 hours after infusion of E. coli endotoxin 2 micrograms kg-1 BW. Following infusion of endotoxin, the number of granulocytes in peripheral blood decreased from 2.44 to 0.064 x 10 l-1 two hours later. Within 5 min after infusion the overall oxidative burst of the peripheral blood granulocytes was increased and the granularity had decreased. Serum cortisol and interleukin-1 beta increased significantly. The radioactivity of labelled cells in the bone marrow and spleen decreased to 83.1% and 91.6% of initial values. At the same time there was a transient sequestration of labelled granulocytes in the lungs reaching 117.6% of initial values. The radioactivity of the liver increased continuously to 118.4%. The results indicate that endotoxin induces an efflux in activated granulocytes from peripheral blood, bone marrow and spleen to the lungs and liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Role of endogenous platelet-activating factor (PAF) in endotoxin-induced portal hypertension in rats.

To determine the role of platelet-activating factor (PAF) in endotoxin-induced portal hypertension, we performed continuous recording of both blood pressure (BP) and portal venous pressure (PVP) in rats following the administration of intravenous PAF (25 ng/kg), intraportal PAF (25 ng/kg), intraportal endotoxin (2 mg/kg), and intraportal endotoxin (2 mg/kg) for 1 min subsequent to pretreatment with a specific PAF-antagonist (CV-6209, 1 mg/kg, i.v.). Basal resting values of both BP (102.3 +/- 9.3 mmHg) and PVP (7.7 +/- 1.2 mmHg) fell rapidly after intravenous infusion of PAF (BP: 36.7 +/- 5.8 mmHg; PVP: 5.7 +/- 0.8 mmHg) and followed by gradual return. Intraportal PAF infusion elicited a rapid but less severe depression of BP (57.2 +/- 9.4 mmHg) as compared with intravenous PAF infusion, whereas PVP was increased transiently around 4 min after treatment (11.0 +/- 5.3 mmHg). A similar degree of PVP elevation (10.7 +/- 2.0 mmHg) was observed between 8 and 20 min after intraportal administration of endotoxin. Depression of BP was initiated 12 min after endotoxin administration but was not severe (76.6 +/- 12.8 mmHg). CV-6209 significantly alleviated the endotoxin-induced elevation of PVP and completely inhibited the hypotension. These observations suggest that: (i) PAF-induced elevation of PVP is a direct response of the liver to PAF; and (ii) endogenous PAF plays an important role in the endotoxin-induced portal hypertension.

Animals↗
PubMed2005

Evidence against a role for endotoxin in the hepatic encephalopathy of rats with thioacetamide-induced fulminant hepatic failure.

BACKGROUND AND AIMS: Endotoxin has been proposed to participate in the development of hepatic encephalopathy. However, there is no published data concerning the effects of endotoxin neutralization on the degree of hepatic encephalopathy. The present study investigated the effect of chronic intraperitoneal injection of polymyxin B, a neutralizing antagonist of endotoxin, on hepatic encephalopathy in rats with thioacetamide (TAA)-induced fulminant hepatic failure. METHODS: Male Sprague-Dawley rats weighing 300-350 g were used. Fulminant hepatic failure was induced by intraperitoneal injection of TAA (350 mg/kg/day) for 3 days. Two series of rats were designed to compare the effects of low dose (0.1 mg) or high dose (0.2 mg) intraperitoneal polymyxin B administration versus normal saline (NS) on hepatic encephalopathy. The injection was twice daily started from 2 days prior to TAA administration and lasted for 5 days. Severity of encephalopathy was assessed by the counts of motor activity in an Opto-Varimex animal activity meter. Plasma levels of endotoxin and tumor necrosis factor-alpha (an index of liver injury) were measured by Limulus assay and the ELISA method, respectively. RESULTS: Neutralization of endotoxin by either low dose or high dose polymyxin B administration did not significantly alleviate the degree of hepatic encephalopathy, as represented by the counts of motor activities (P > 0.05). Plasma levels of endotoxin and tumor necrosis factor-alpha were comparable between rats treated with polymyxin B or NS (P > 0.05). CONCLUSION: Our findings do not support the notion that endotoxin plays a major role in the pathogenesis of hepatic encephalopathy in rats with TAA-induced fulminant hepatic failure.

Animals↗
PubMed1977

Feline endotoxin shock: effects of methylprednisolone on kininogen-depletion, on the pulmonary circulation and on survival.

1 Escherichia coli endotoxin, administered intravenously in a dose of 2 mg/kg to pentobarbitone anaesthetized, artificially ventilated cats resulted in pulmonary hypertension, systemic hypotension and an immediate (1-2 min) 30-40% reduction in plasma kininogen, an effect which probably indicates a release of plasma kinins. 2 Methylprednisolone (30 mg/kg), when administered 30 min before endotoxin, did not influence the endotoxin-induced pulmonary hypertension or systemic hypotension but completely prevented the depletion of plasma kininogen. 3 In spontaneously breathing cats, methylprednisolone, administered 30 min after endotoxin, caused a rapid repletion of kininogen and prolonged survival (47% at 6 h compared to 10% in the endotoxinalone animals). Methylprednisolone did not appear to influence lactate production or the hyperventilation observed during the delayed endotoxin shock phase. 4 It is concluded t,at methylprednisolone does not prevent the release, by endotoxin, of a pulmonary vasoconstrictor prostaglandin, or its effects, but that perhaps by preventing kinin release it may reduce endotoxin-induced capillary leakage.

Animals↗
PubMed1987

The involvement of platelet activating factor in endotoxin-induced pulmonary platelet recruitment in the guinea-pig.

1 Exposure of conscious guinea-pigs to an aerosol of endotoxin (25-100 micrograms ml-1) resulted in a dose-related, progressive accumulation of platelets in the thoracic region. Accumulation of 111indium oxine labelled erythrocytes was not observed following exposure to an aerosol of endotoxin (50 micrograms ml-1). 2 Pretreatment of guinea-pigs with the selective platelet activating factor (Paf)-antagonists. CV-3988 or brotizolam resulted in a dose-related inhibition of endotoxin-induced pulmonary platelet recruitment. Pretreatment of guinea-pigs with the selective Paf-antagonist BN 52021 resulted in significant inhibition of endotoxin-induced pulmonary platelet recruitment, although the effects of BN 52021 were not dose-related. 3 Pretreatment of guinea-pigs with indomethacin at doses known to inhibit cyclo-oxygenase did not inhibit endotoxin-induced pulmonary platelet recruitment, whereas higher doses of indomethacin produced a reduction in platelet recruitment in the lung. 4 Pretreatment of guinea-pigs with the anticoagulant heparin and the prostacyclin analogue ZK 36374 inhibited endotoxin-induced platelet recruitment. 5 These observations suggest that endotoxin-induced pulmonary platelet recruitment in the guinea-pig is secondary to the release of platelet activating factor, but not to cyclo-oxygenase products of arachidonic acid and may also involve activation of the coagulation cascade.

Animals↗
PubMed1988

Indomethacin potentiates endotoxin-induced blood flow reduction and histological injury in rat gastric mucosa.

1. The effect of the intravenous administration of lipopolysaccharide from Salmonella typhosa endotoxin on arterial blood pressure (BP), gastric mucosal blood flow (GMBF) and gastric damage was studied in anaesthetized rats. The effect of the inhibition of endogenous prostaglandin generation by indomethacin on these parameters was also investigated in this model of endotoxin shock. 2. A similar and dose-dependent percentage of reduction in BP and GMBF was observed 5 min after a bolus injection of 20 or 30 mg kg-1 endotoxin. A transient recovery in GMBF at 15 min was observed followed by a second fall at 30 min, at a time when BP was slowly increasing. 3. Pretreatment with indomethacin (5 mg kg-1, s.c.) one hour before the administration of 30 mg kg-1 endotoxin, significantly augmented the reduction in GMBF without affecting the reduction in BP. 4. The gastric damage, assessed histologically, was similar and confined to the superficial mucosa 30 min after the administration of 20 or 30 mg kg-1 endotoxin. The histologically-assessed damage was significantly greater in indomethacin pretreated rats injected with 30 mg kg-1 endotoxin. 5. These findings suggest that endogenous prostaglandin generation plays a protective role in endotoxin-induced gastric mucosal microcirculatory disturbances and mucosal damage.

Animals↗
PubMed1990

Relationships between tumour necrosis factor, eicosanoids and platelet-activating factor as mediators of endotoxin-induced shock in mice.

1. The toxicity of intravenous recombinant human tumour necrosis factor (rhTNF), a TNF fragment (TNF114-130), endotoxin and combinations of rhTNF or TNF114-130 were tested in mice. Neither rhTNF nor TNF114-130 was lethal alone, but when combined with a non-lethal dose of endotoxin, rhTNF provoked dose-dependent mortality, as did higher doses of endotoxin alone. 2. Both the toxicity and the vasopermeability changes induced by endotoxin alone were blocked by the platelet-activating factor (PAF) antagonist BN52021, indomethacin or the dual cyclo-oxygenase/lipoxygenase inhibitor BW755C. 3. The lethality of the combined low dose endotoxin/rhTNF challenge was unaffected by pretreatment with BN52021, indomethacin or BW755C, or by treatment at 6 h intervals with BN52021 or BW755C. 4. The results of these studies suggest that TNF, a putative, early mediator of septic or endotoxin shock, cannot by itself mimic all of the effects of bacterial endotoxin in the model used in this study. Apparently, TNF works synergistically with other mediators whose release is stimulated by endotoxin. 5. The results also suggest that the mechanism of shock production by the rhTNF/endotoxin combination in mice is not dependent on the early stimulation of eicosanoid or PAF synthesis by rhTNF.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1990

Endotoxin-induced impairment of vasopressor and vasodepressor responses in the pithed rat.

1. Effects of E. coli endotoxin on vascular responsiveness to a variety of agents were compared with those of the calcium channel blocking drug nicardipine in pithed rats. 2. Infusion of endotoxin (250 micrograms kg-1 h-1) produced a fall in mean arterial blood pressure (8 mmHg). A similar fall (11 mmHg) was seen in rats receiving nicardipine (1.0 mg kg-1). 3. Endotoxin impaired responsiveness to vasopressin, phenylephrine and cirazoline, producing a shift to the right in the dose-response curves without any change in the maximum response. Responsiveness to 5-hydroxytryptamine (5-HT) and to the alpha 2-adrenoceptor agonists clonidine and BHT 933, was also impaired with a marked reduction in their maximum responses. The dose-response curve to the pressor effects of endothelin was not significantly modified. 4. Nicardipine produced a similar pattern of impairment of responsiveness to these agents to that produced by endotoxin. However, nicardipine also shifted the pressor dose-response curve to endothelin to the right with no significant alteration in its maximum response. 5. The pressor responses to endothelin and to 5-HT were, respectively, preceded and followed by dose-dependent depressor responses, which were markedly reduced by endotoxin and nicardipine. 6. The concomitant infusion of arginine vasopressin (0.64 iu kg-1 h-1) prevented endotoxin-induced hypotension and also prevented the impairment in responsiveness to cirazoline and to BHT 933. 7. The similarity of the pattern of impaired pressor responsiveness (except in relation to endothelin) and depressor responsiveness produced by endotoxin and nicardipine may be consistent with a common mechanism of action.

Animals↗
PubMed1996

Effects of selective phosphodiesterase 3 inhibition in the perfused liver of the rat after endotoxin treatment.

1. This study was designed to investigate the role of rat phosphodiesterase 3 (RPDE3) in regulation of liver metabolism in sepsis. We studied the effects of the phosphodiesterase 3 inhibitor (PDI), enoximone, alone and in combination with regulating factors of hepatic carbohydrate metabolism and bile secretion in the perfused liver of rats treated 4 h earlier with endotoxin. In addition, cyclic AMP and cyclic GMP levels were determined in the effluate and bile by radio immunoassay methods. 2. After endotoxin treatment, infusion of enoximone at three concentrations (1 microM, 10 microM) resulted in an increased glucose output from -1.4 +/- 0.9 to 7.8 +/- 2.5 mumol l-1 20 min-1. Bile acid-independent bile flow increased also, in a dose-dependent manner. 3. In untreated livers, cyclic AMP release increased in the effluate from 1000 +/- 73 fmol g-1 min-1 to 1710 +/- 143 fmol g-1 min-1 when enoximone (10 microM) was administered. In bile from untreated livers, the level of cyclic AMP was also significantly increased by enoximone. After endotoxin treatment, the enoximone (10 microM) effect on cyclic AMP levels in effluate and bile was greatly reduced. Levels of cyclic GMP in the effluate and bile appeared unchanged in the presence of enoximone. 4. During co-infusion of glucagon (1 nM) and enoximone (10 microM), cyclic nucleotide levels in the effluate and bile of livers after endotoxin treatment were determined. In the effluate, cyclic AMP release increased from 827 +/- 144 fmol g-1 min-1 to 17802 +/- 2821 fmol g-1 min-1 when glucagon was administered. The presence of enoximone enhanced cyclic AMP further to 41696 +/- 920 fmol g-1 min-1. The same changes in cyclic AMP release were found in bile. Levels of cyclic GMP in the effluate and bile were not significantly affected by the administration of glucagon and the PDI. 5. Glucose release was determined during glucagon, sympathetic nerves stimulation and phenylephrine administration in the presence and absence of enoximone. The addition of enoximone to glucagon increased glucose release by 8.2 +/- 2.8 mumol g-1 20 min-1, without alteration of lactate balance. The PDI enhanced the glycogenolytic effects of nerve stimulation and of phenylephrine, accompanied by a reduction in lactate production. 6. Enoximone significantly enhanced the bile acid independent bile flow after glucagon, nerves stimulation and after administration of phenylephrine. Bile acid secretion was unaffected by the PDI. The vasoconstrictor effect of nerve stimulation was reduced by the PDI. 7. We conclude that endotoxin treatment reduces the ability of the PDI, enoximone, to increase cyclic AMP release in the perfused liver. The significant increase in cyclic AMP release after stimulation with glucagon and enoximone favours the view that RPDE3 is involved in the degradation of cyclic AMP in the liver after exposure to endotoxin. Additionally, the inhibition of the RPDE3 results in glucose release, vasodilatation and choleresis in endotoxin pretreated livers.

Animals↗
PubMed1996

The contribution of nitric oxide to endotoxin-induced ocular inflammation: interaction with sensory nerve fibres.

1. The actions of nitric oxide (NO) have been investigated in an endotoxin-evoked ocular inflammatory model in the rabbit, with particular emphasis on the relationship between NO, sensory nerves (C-fibres) and the C-fibre neuropeptides, calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase activating peptide (PACAP). 2. Endotoxin, injected intravitreally, evoked inflammatory responses, i.e. conjunctival hyperaemia, miosis and protein extravasation, reflected by the aqueous flare response (AFR). In control rabbits, the maximum AFR was 66.5 +/- 9.5 (arbitrary units). Pretreatment with the NO synthase (NOS) inhibitor, NG-nitro-L-arginine (L-NAME, 200 mg kg-1) given by intravenous injection, inhibited the endotoxin-evoked responses; the AFR was 16.5 +/- 1.9 (n = 8, P < 0.001) and the conjunctival hyperaemia was abolished. 3. Endotoxin-evoked ocular inflammation is associated with the release of CGRP and PACAP from C-fibres. In the eyes challenged with endotoxin, the concentrations of PACAP-27, -38 and CGRP in the aqueous humour were 58.2 +/- 10.9, 54.4 +/- 12.4 and 5526 +/- 519 (pmoll'), respectively. L-NAME inhibited the release of PACAP-27, -38 and CGRP; the concentrations were 14.3 +/- 2.5, 13.5 +/- 2.5 and 510 +/- 67 (pmoll-1), respectively (n = 8, P < 0.01 or 0.001). 4. Intravitreal injection of 0.3 nmol CGRP induced conjunctival hyperaemia and AFR; the maximum AFR was 140.2 +/- 11.4. L-NAME suppressed the response induced by CGRP; the AFR was 23.4 +/- 5.5 (n = 8, P < 0.001). L-NAME abolished the conjunctival hyperaemia induced by PACAP-27 and -38 (0.3 nmol) and reduced the AFR. 5. The inflammatory cells that infiltrated the uvea, cornea and aqueous humour in large numbers in response to intravitreal injection of endotoxin were found to express inducible NOS. L-NAME prevented the appearance of such cells. 6. Our findings suggest that NO plays an important role in the endotoxin-evoked ocular inflammation in the rabbit: NO activates C-fibres causing release of C-fibre neuropeptides into the aqueous humour. In addition, NO mediates scme of the ocular effects of CGRP and PACAP, since L-NAME suppressed the AFR induced by these peptides.

Animals↗
PubMed1992

Tumor necrosis factor in alcohol enhanced endotoxin liver injury.

Endotoxin administration causes liver injury. Patients with alcoholic liver disease frequently have portal vein and systemic endotoxemia, and some investigators have suggested that endotoxin plays an etiologic role in alcoholic liver injury. Many of the metabolic effects of endotoxin are mediated by the cytokine tumor necrosis factor (TNF). It was the purpose of this study to determine whether TNF plays a role in ethanol-enhanced endotoxin liver injury. Rats were fed either a diet in which 36% of the calories were from ethanol or an isocaloric control diet. After 6 weeks, groups of 10 rats were intravenously injected with either saline, 1 mg/kg endotoxin, or 30 micrograms/kg of a prostaglandin E1 (PGE1) analogue + 1 mg/kg endotoxin 24 hr prior to sacrifice. Ethanol/endotoxin-treated rats had significantly higher liver enzyme levels (ALT: 1064 +/- 355 IU/liter, AST: 2024 +/- 515 IU/liter) compared with isocaloric/endotoxin controls (ALT: 237 +/- 54 IU/liter, AST: 602 +/- 80 IU/liter). Ethanol/endotoxin rats also had significantly higher peak serum TNF concentrations (992 +/- 200 units/ml) compared with isocaloric/endotoxin controls (344 +/- 96 units/ml). Pretreatment of ethanol/endotoxin rats with PGE1 caused significant attenuation of liver injury (ALT: 267 +/- 64 IU/liter, AST: 612 +/- 77 IU/liter) and a diminished serum TNF response. In contrast to chronic ethanol administration, acute gavage with 2 mg/kg ethanol (30% w/v) followed by intravenous injection of 2 mg/kg endotoxin produced significantly lower peak serum TNF concentrations (401 +/- 76 units/ml) than gavage with distilled water (1152 +/- 208 units/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Alprostadil↗
PubMed1983

The influence of endotoxin in vitro on hepatic macrophage lysosomal enzyme release in different rat models of hepatic injury.

Since bacterial endotoxin is known to be involved in the pathogenesis of hepatic injury, the influence of endotoxin on lysosomal enzyme production by hepatic macrophages has been investigated. Macrophages have been isolated from the livers of normal rats, from the livers of rats given stilboestrol subcutaneously 4 days previously and from the livers of rats given Corynebacterium parvum intravenously 6 days previously. Following isolation and overnight culture, the macrophages have been maintained in in vitro culture for a further 24 h and the production of N-acetyl-beta-glucosaminidase (NAG) has been measured. Histological assessment has shown that in stilboestrol model an approximate doubling of sinusoidal cell numbers occurs and in the C. parvum model a heavy mononuclear cell infiltrate is present, together with granuloma formation. These changes are reflected in the numbers of macrophages isolated from the respective models. Levels of NAG production by resident macrophages from normal livers are low (0.25 +/- 0.05 nmol substrate hydrolysed/microgram cell protein/h) and unchanged following endotoxin exposure (0.25 +/- 0.05 units). Macrophages isolated from the stilboestrol model show levels of NAG production similar to normal (0.34 +/- 0.06 units), but this increases significantly following exposure to endotoxin (0.42 +/- 0.07 units). Macrophages from the C. parvum model demonstrate markedly enhanced production (0.61 +/- 0.09 units), but this does not increase significantly following endotoxin exposure (0.65 +/- 0.09 units). In contrast to macrophages from normal rat livers, macrophages recently recruited in the stilboestrol model demonstrate enhanced lysosomal enzyme production following endotoxin exposure. It is suggested that endotoxin, as well as other mediators of macrophage activation, may promote hepatic damage through this influence on newly recruited macrophages.

Acetylglucosaminidase↗
PubMed1983

The effect of pretreatment with vitamin E on the effects of endotoxin in rat.

Twenty male rats weighing about 100g were treated subcutaneously with 25 mg alpha-tocopherol acetate. The rats were given 0.4 mg/100 g endotoxin intraperitoneally 24 hrs after the pretreatment, and were sacrificed 18 hrs after the endotoxin injection. The lipid peroxide level as evaluated by the TBA-value remained at the no-treatment level. In a similar group of rats not pretreated but given the same dose of endotoxin intraperitoneally, the TBA-value rose significantly. There were no statistically significant differences in the mean plasma ALAT and OCT activities or in the mean liver or plasma Zn concentrations between the endotoxin treated groups. The plasma OCT and ALAT activities were significantly correlated with the liver TBA-values in both endotoxin-treated groups but the plasma Zn and OCT, or plasma Zn and ALAT were significantly correlated only in the group pretreated with vitamin E. In a control group of 20 animals not treated with either endotoxin or vitamin E the plasma Zn and vitamin E concentrations were statistically significantly (P less than 0.05) correlated. It is suggested that the endotoxin effect on the liver is probably mediated by prostaglandin-like substances.

Alanine Transaminase↗
PubMed1995

Role of Ca2+ on endotoxin-sensitivity by galactosamine challenge: lipid peroxide formation and hepatotoxicity in zymosan-primed mice.

This study was investigated to clarify the role of intracellular Ca2+ following endotoxin treatment (1 mg/kg, intraperitoneally) to D-galactosamine-sensitized mice (400 mg/kg, intraperitoneally), and to observe lipid peroxide levels, an index of hepatotoxicity, in endotoxin/galactosamine (Ga1N)-challenged mice under activation of macrophages, especially Kupffer cells, by zymosan. The liver lipid peroxide level and serum glutamic pyruvic transminase activity in mice 18 hr after administration of endotoxin/Ga1N were markedly higher than those in mice treated only with endotoxin. In spite of an increase in lipid peroxide formation, there was little or no effect of Ga1N administration on xanthine oxidase and superoxide dismutase activities in mice given endotoxin. However, the injection of verapamil (10 mg/kg, subcutaneously) markedly decreased lipid peroxide levels in liver of endotoxin/Ga1N-injected mice. In the mice given a Ca(2+)-deficient diet, lipid peroxide level in liver after endotoxin/Ga1N injection was markedly decreased compared to that in mice fed a normal diet. Administration of dexamethasone (200 micrograms/kg, intraperitoneally) in mice 1 hr before treatment with endotoxin/Ga1N did not induce lipid peroxide formation. Administration of endotoxin to Ga1N-treated mice resulted in a higher level of liver cytosolic free Ca2+ ([Ca2+]i) than that in endotoxin-treated mice. On the other hand, Ca(2+)-ATPase activity in liver plasma membrane in the endotoxin/Ga1N-treated mice was markedly decreased as compared with endotoxin alone. On the contrary, the Ca(2+)-ATPase activity in liver mitochondria was higher in endotoxaemic mice treated with GA1N than in mice given endotoxin alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine Transaminase↗
PubMed1998

Endotoxin increases oxidative injury to proteins in guinea pig liver: protection by dietary vitamin C.

Current information suggests that oxidative damage plays a key role in septic shock induced by endotoxin. This raises the possibility that dietary antioxidant vitamins could protect against endotoxin damage. In this study, the effects of endotoxin administration on protein and lipid oxidative damage and endogenous antioxidants were studied in the liver of guinea pigs previously supplemented with marginal or optimum levels of dietary vitamin C, vitamin E or both. Vitamins C and E inhibited in vitro lipid peroxidation in endotoxin-treated animals. Endotoxin significantly increased oxidative damage to liver proteins in animals receiving low doses of both vitamins, a result described here for the first time. This increase was totally prevented in guinea pigs supplemented with vitamin C alone or in combination with vitamin E, a treatment which strongly increased liver ascorbate. Vitamin C caused small significant increases in superoxide dismutase and glutathione, increased uric acid, and synergically increased alpha-tocopherol levels in vitamin E-supplemented animals treated with endotoxin. The results show that dietary vitamin C protects against endotoxin-induced oxidative damage to proteins in the guinea pig liver. This seems mainly due to a direct protective effect of the increased hepatic ascorbate levels present in vitamin C-supplemented animals.

Animals↗
PubMed1998

Extracorporeal endotoxin removal by polymyxin B immobilized fiber cartridge: designing and antiendotoxin efficacy in the clinical application.

We have developed an extracorporeal hemoadsorption cartridge, the PMX cartridge, to eliminate endotoxin from peripheral blood circulation. As an adsorbent, a polymyxin B covalently immobilized fiber (PMX-F) was developed. After the optimization of the condition of immobilization, fixed polymyxin B maintained its ability to adsorb endotoxin and its bactericidal activity. PMX-F could detoxify many kinds of endotoxin in vitro. Fixed polymyxin B was estimated to interact with the lipid A portion of endotoxin. Utilization of fibrous adsorbents enabled us to design the PMX cartridge with a large surface area and low blood pressure drop in the blood flow compartment and to apply it safely to the direct hemoperfusion procedure. In Japan, the PMX cartridge is now being clinically applied as one of the therapeutical interventions for sepsis, septic shock, and septic multiple organ failure. In multicenter clinical studies, the blood endotoxin level has been significantly decreased. Accompanied with elimination of endotoxin, hemodynamic abnormalities such as low blood pressure and low systemic vascular resistance were significantly improved. In more recent multicenter studies, the average number of failed organs; severity of illness score, such as Goris score; and vasopressor dosage were significantly decreased. The PMX cartridge is expected to be effective in the intervention for the treatment of septic shock. Endotoxin may be one of the therapeutical targets for the treatment of sepsis.

Adolescent↗
PubMed2005

Endotoxins in the prostatic secretions of chronic prostatitis patients.

AIM: To evaluate the clinical significance of the quantitative determinations of endotoxins in the expressed prostatic secretions (EPS) of chronic prostatitis (CP) patients. METHODS: The EPS of 45 patients with CP and 15 normal volunteers were obtained for microscopic examination, bacterial culture and endotoxin determination. The level of endotoxins was determined by the Limulus-amebocyte-lysate test with chromogenic substrate. RESULTS: Patients with CP had higher mean levels of endotoxins in EPS than normal volunteers [52.06 +/- 32.83 EU/L vs. 4.77 +/- 4.14 EU/L (P <0.05)]. The levels of endotoxins in CP type II, type IIIa and type IIIb were 68.62 +/- 34.78 EU/L, 45.30 +/- 23.33 EU/L and 15.83 +/- 5.31 EU/L, respectively [type II vs. type IIIa (P >0.05), type IIIb vs. normal controls (P <0.05), type II/type IIIa vs. normal controls P >0.05)]. CONCLUSION: CP patients have elevated levels of endotoxins in the EPS, which suggests that inflammation is a feature of this disease. EPS endotoxin determination is not only helpful in diagnostic confirmation, but also in evaluating the response to treatment in CP patients.

Adult↗