Lipopolysaccharide-induced down-regulation of organic anion transporting polypeptide 4 (Oatp4; Slc21a10) is independent of tumor necrosis factor-alpha, Interleukin-1beta, interleukin-6, or inducible nitric oxide synthase.

Organic anion transporting polypeptide 4 (Oatp4; Slc21a10) is expressed almost exclusively in liver, where it mediates uptake of a variety of compounds, including bile acids, as well as other endo- and xenobiotics, across hepatic sinusoidal membranes in a Na+-independent manner. Lipopolysaccharide (LPS) has been shown to decrease Oatp4 mRNA levels in a dose- and time-dependent manner in Toll-like receptor 4 (TLR4)-normal (C3H/OuJ) mice, but not in TLR4-mutant (C3H/HeJ) mice. Moreover, after LPS administration, serum concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) are markedly lower in TLR4-mutant mice than in TLR4-normal mice. Thus, TLR4 is considered an upstream mediator of LPS-induced decrease in mouse Oatp4 mRNA. LPS is thought to alter liver gene expression through LPS-induced cytokines or nitric oxide (NO). TNF receptor p55 (TNFRp55) and type I IL-1 receptor (IL-1RI) mediate the biological functions of TNF-alpha and IL-1beta, respectively. Therefore, to determine whether endogenous cytokines or NO are mediators of LPS-induced down-regulation of Oatp4, Oatp4 mRNA levels were determined in mice deficient in the TNFRp55, IL-1RI, IL-6, or inducible nitric oxide synthase (iNOS) after LPS administration. Mice homozygous for a targeted deletion of genes for TNFRp55, IL-1RI, IL-6, or iNOS exhibited similar decreases in Oatp4 mRNA levels as wild-type mice after LPS administration. Moreover, in mouse hepatoma cells, treatment with TNF-alpha, IL-1beta, or IL-6 individually or in combination did not suppress activity of mouse Oatp4 promoter (-4.8 kb to +30). Therefore, LPS-induced down-regulation of Oatp4 appears to be independent of TNF-alpha, IL-1beta, IL-6, or iNOS.     

Suppression of endotoxin-induced renal tumor necrosis factor-alpha and interleukin-6 mRNA by renin-angiotensin system inhibitors

The present study was designed to clarify the role of angiotensin II (Ang II) in modulating renal tumor necrosis factor (TNF)-alpha and interleukin-6 (IL-6) production and to investigate the effect of one dose of Ang II inhibitor on cytokines production following lipopolysaccharide (LPS) to cause endotoxemia. Two studies were performed: 1) Ang II was infused intravenously at a rate of 0.2 microg/kg per minute for 4 h in rats and then kidneys were collected to assay TNF-alpha and IL-6 mRNA levels; 2) Four-week-old Wistar rats pre-treated with angiotensin-converting enzyme inhibitor, enalapril, or type I Ang II-receptor antagonist, TCV-116, were injected with LPS (0.1, 0.5, 1.0 mg, i.p.), and then 2 or 4 h later, kidneys were collected to assay TNF-alpha, IL-6, renin and angiotensinogen mRNA levels. After a 4-h intravenous infusion of Ang II, renal TNF-alpha or IL-6 mRNA level significantly increased 1.9-fold or 2.1-fold (each P<0.05) to the control level, respectively. LPS stimulated TNF-alpha, IL-6 and angiotensinogen mRNA levels in the kidney but in rats given enalapril or TCV-116, LPS-induced IL-6 and TNF-alpha mRNA levels were completely suppressed (each P<0.05). This suggests that a single dose of renin-angiotensin system inhibitor suppressed renal IL-6 and TNF-alpha production and may prevent cytokine-induced renal damage during endotoxemia.     

Amplified proinflammatory cytokine expression and toxicity in mice coexposed to lipopolysaccharide and the trichothecene vomitoxin (deoxynivalenol).

A single oral exposure to the trichothecene vomitoxin (VT) has been previously shown in the mouse to increase splenic mRNA levels for several cytokines in as little as 2 h. Since one underlying mechanism for these effects likely involves superinduction of transiently expressed cytokine genes, VT may also potentially amplify cytokine responses to inflammatory stimuli. To test this possibility, the effects of oral VT exposure on tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1beta expression were measured in mice that were intraperitoneally injected with lipopolysaccharide (LPS), a prototypic inflammatory agent. As anticipated, VT alone at 1, 5, and 25 mg/kg body weight increased splenic mRNA expression of all three cytokines after 3 h in a dose-response fashion. LPS injection at 1 and 5 mg/kg body weight also induced proinflammatory cytokine mRNA expression. There was a synergistic increase in TNF-alpha splenic mRNA levels in mice treated with both VT and LPS as compared to mice treated with either toxin alone, whereas the effects were additive for IL-6 and IL-1beta mRNA expression. When relative mRNA levels were examined over a 12-h period in mice given LPS (1 mg/kg) and/or VT (5 mg/kg), significant enhancement was observed up to 6, 12, and 3 h for TNF-alpha, IL-6, and IL-1beta, respectively. When plasma cytokine concentrations were measured, TNF-alpha was found to peak at 1 h and was significantly increased at 1, 3, and 6 h if mice were given LPS and VT, whereas LPS or VT alone caused much smaller increases in plasma TNF-alpha Plasma IL-6 peaked at 3 h in LPS, VT, and LPS/VT groups, with the combined toxin group exhibiting additive effects. Plasma IL-1beta was not detectable. The potential for VT and LPS to enhance toxicity was examined in a subsequent study. Mortality was not observed up to 72 h in mice exposed to a single oral dose of VT at 25 mg/kg body weight or to an intraperitoneal dose of LPS at 1 or 5 mg/kg body weight; however, all mice receiving VT and either LPS dose became moribund in less than 40 h. The principal histologic lesions in the moribund mice treated with VT and LPS were marked cell death and loss in thymus, Peyer's patches, spleen, and bone marrow. In all of these lymphoid tissues, treatment-induced cell death had characteristic histologic features of apoptosis causing lymphoid atrophy. These results suggest that LPS exposure may markedly increase the toxicity of trichothecenes and that the immune system was a primary target of these interactive effects.     

水杨酸钠对胰岛素抵抗大鼠肝脏核因子-κB及炎症因子表达的影响

目的观察水杨酸钠对胰岛素抵抗大鼠肝脏胰岛素敏感性的影响。方法大鼠随机分为3组:分别给大鼠静脉输注脂肪乳(脂肪乳组),脂肪乳+水杨酸钠(实验组)和生理盐水组,并在输注后2 h,进行清醒状态下扩展高胰岛素-正血糖钳夹术,检测肝脏组织中NF-κB及IL-6、TNF-α、SOCS-3 mRNA的表达。结果脂肪乳组大鼠钳夹稳态下,内生葡萄糖产物(EGP)较基础状态降低比率仅是生理盐水组大鼠的38%,水杨酸钠提高EGP降低幅度明显(P<0.01),改善了肝脏胰岛素敏感性。脂肪乳组肝细胞核NF-κB表达量是生理盐水组2.4倍,肝组织中IL-6、TNF-α及SOCS-3 mRNA表达较生理盐水组升高,输注水杨酸钠使核内NF-κB较输注脂肪乳下降40%,炎症因子表达相应降低(P<0.01)。结论水杨酸钠可抑制肝脏组织NF-κB活化,进而降低炎症因子蓄积,发挥改善肝脏胰岛素抵抗的作用。     

Increment of plasma soluble CD14 level in carrageenan-primed endotoxin shock model mice

CD14 is membrane-associating or free soluble glycoprotein which recognizes lipopolysaccharide (LPS) and is assumed to be involved in the onset of endotoxin shock. There are some reports suggesting the relationship between increased expression of CD14 in infectious or inflammatory diseases. However, little has been reported concerning the soluble CD14 (sCD14) level, especially in mice. In this study, we measured the plasma level of sCD14, TNF-alpha and IL-6 in the iota-carrageenan (CAR)-primed endotoxin shock model in addition to the D-galactosamine (D-galN)-primed endotoxin shock model mice. It was confirmed that all mice were dead within 12 h after a higher dose of LPS-treatment in both animal models. The level of TNF-alpha, IL-6 and sCD14 significantly increased in the CAR-primed endotoxin shock model mice. However, the D-galN-primed endotoxin shock model mice showed only a slight increment of TNF-alpha and IL-6 level, and sCD14 was below the detectable level. In the examination using several doses of LPS in CAR-primed model mice, IL-6 and sCD14 were increased dependent on the LPS dose, but TNF-alpha remained at an almost equal level at any dose of LPS in this study condition. In conclusion, the production of TNF-alpha, IL-6 and sCD14 was significantly enhanced in the CAR-primed model mice, compared to the D-galN-primed model mice. Therefore, these data indicate the possibility that the sCD14 level did not increase consistently, even under a fatal condition in endotoxin shock. Also, CAR-primed endotoxin shock would be an important experimental model to examine the elevation mechanisms for sCD14 and IL-6 production.     

Regulation of the hepatic multidrug resistance gene expression by endotoxin and inflammatory cytokines in mice

P-glycoprotein (PGP), an ATP-dependent membrane transporter is found in epithelial tissues of the liver, kidneys, intestine and blood-brain barrier. In tumor cells, PGP is often overexpressed and confers multidrug resistance toward cancer chemotherapeutics. It has been previously shown in rats that induction of an inflammatory response evokes a decrease in hepatic expression of PGP. In order to identify the inflammatory mediators involved in this phenomenon, we examined the influence of experimentally induced inflammation and pro-inflammatory cytokines (interleukin (IL)-6, IL-1beta and tumor necrosis factor (TNF)-alpha) on the hepatic expression of PGP in mice. A significant reduction in the hepatic expression of mdr1a, mdr1b, mdr2 and spgp genes were seen in endotoxin (lipopolysaccharide (LPS)) and turpentine-treated mice. Similarly, IL-6-treated mice displayed a 70% reduction in protein expression and a 40-70% reduction in the mRNA levels of all PGP mdr isoforms. Administration IL-1beta caused an increase in both mdr1b mRNA and protein expression, however, mRNA levels of mdr1a, mdr2 and spgp were significantly reduced. Administration of TNF-alpha also caused increases in mdr1b mRNA. These findings indicate that IL-6 plays a principal role in the downregulation of PGP that is observed in the livers of mice during an inflammatory response.     

Beneficial effects of histidine and carnosine on ethanol-induced chronic liver injury.

Alleviative effects of histidine and carnosine in mice against ethanol-induced oxidative and inflammatory was examined. After chronic alcoholic liver injury was induced, histidine and carnosine at 0.5, 1, 2g/L were added to the drinking water for 3 weeks. Results showed that the post-intake of histidine or carnosine markedly decreased alanine aminotransferase and aspartate aminotransferase activities (P<0.05). Ethanol treatment increased malondialdehyde (MDA) level, decreased glutathione (GSH) content and catalase and glutathione peroxidase (GPX) activities, and increased cytochrome P450 2E1 (CYP2E1) activity in liver (P<0.05). The post-intake of histidine and carnosine significantly decreased MDA formations, increased GSH content, enhanced catalase and GPX activities, and suppressed CYP2E1 activity (P<0.05), in which the effects on catalase and CYP2E1 activities were dose-dependent (P<0.05). Ethanol treatment elevated hepatic levels of c-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) (P<0.05), the post-intake of histidine and carnosine significantly and dose-dependently diminished the release of CRP, IL-6, and TNF-alpha (P<0.05). Ethanol treatment caused down-regulation in both catalase and GPX mRNA expression, and up-regulated both IL-6 and TNF-alpha mRNA expression (P<0.05). Histidine and carnosine post-treatments significantly and dose-dependently upregulated catalase mRNA, and down-regulated mRNA expression of IL-6 and TNF-alpha (P<0.05). Based on the observed anti-oxidative and anti-inflammatory effects, the supplement of histidine or carnosine might be helpful for the treatment of chronic alcoholic liver injury.     

油酰乙醇胺对脂多糖诱导的THP-1细胞炎症因子表达的影响

目的探讨油酰乙醇胺(OEA)对细菌脂多糖(LPS)诱导的人急性白血病单核细胞(THP-1)中前炎症因子TNF-α、IL-1β、IL-6表达的影响,并初步探讨OEA作为过氧化物酶体增殖物激活受体-α(PPAR-α)激动剂参与对炎症调节的作用机制。方法体外培养的THP-1细胞,分别加入不同浓度的OEA(10,20,40μmol/L)或非诺贝特(100μmol/L)共同孵育1 h后,用1μg/mL LPS分别诱导6或24 h。采用RT-PCR、实时定量PCR和酶联免疫吸附检测测定细胞中TNF-α、IL-1β、IL-6 mRNA和蛋白的表达的变化,并使用实时定量PCR及Western blot方法检测PPAR-α及Toll样受体4(TLR4)的mRNA和蛋白的表达。结果相对于正常THP-1细胞,LPS诱导后细胞中炎症因子(TNF-α、IL-1β、IL-6)表达明显增加。OEA对TNF-α、IL-1β、IL-6 mRNA和蛋白的表达有抑制作用,并呈现出一定的剂量依赖性。且OEA在激活PPAR-α表达的同时能够抑制TLR4的表达。结论 OEA对LPS诱导的炎症反应有抑制作用,其机制可能与激活PPAR-α,下调TLR4的表达有关。     

Interference with growth hormone stimulation of hepatic cytochrome P4502C11 expression in hypophysectomized male rats by 3-methylcholanthrene

Cytochrome P450 2C11 (CYP2C11) is a sexually dimorphic liver enzyme whose expression is regulated by the male pulsatile pattern of growth hormone (GH) secretion. Hepatic CYP2C11 expression is down-regulated by polycyclic aromatic hydrocarbons such as 3-methylcholanthrene (MC). An attractive hypothesis as to the mechanism of CYP2C11 down-regulation by aromatic hydrocarbons is the disruption of normal GH signaling by exposure to these compounds. To evaluate the effects of MC on the ability of GH to stimulate hepatic CYP2C11 expression, our approach was to employ GH replacement in male Fischer 344 rats made GH-deficient by hypophysectomy (hypx). Groups of hypx rats received the following treatments: vehicle; GH alone (twice daily, 125 microg/kg sc, days 1-6); MC alone (20 mg/kg gavage, days 1, 3, and 5); and both GH and MC. Rats were euthanized on day 7. As a positive control response, pronounced induction of hepatic CYP1A1 apoprotein was observed in all MC-treated rats. CYP2C11 expression in hypx rats receiving GH alone was increased at the mRNA, apoprotein, and catalytic activity (testosterone 16alpha-hydroxylation) levels, with mRNA and apoprotein levels approaching that of intact male rats. The inability of GH to fully restore CYP2C11 catalytic activity was attributed to the lowered NADPH-cytochrome P450 reductase apoprotein and catalytic activity observed in all hypx rats. CYP2C11 expression in hypx rats receiving both GH and MC was significantly lower at the mRNA, apoprotein, and catalytic activity levels than that observed in hypx rats treated with GH alone, but significantly higher at the mRNA, apoprotein, and catalytic activity levels than that observed in vehicle-treated hypx rats and in hypx rats treated with MC alone. These data suggest that MC interferes with the ability of GH to stimulate CYP2C11 expression. Thus, disruption of GH signaling by aromatic hydrocarbons may represent a mechanism contributing to the suppression of CYP2C11 gene expression.     

Endotoxin induces late increase in the production of pulmonary proinflammatory cytokines in murine lupus-like pristane-primed modelp

Lupus-like syndrome is characterized by multiple organ injuries including lungs and kidneys. Endotoxin induces a transiently intent systemic inflammatory response and indirectly transient acute lung injury in normal condition. However, whether endotoxin may trigger the persistent development of lung injury in chronic, inflammatory lupus-like syndrome compared with normal condition remains unclear. We examined the pulmonary vascular permeability and production of proinflammatory cytokines, such as TNF-alpha, IL-6, IL-10 and IFN-gamma, which play prominent roles in the pathogenesis of lupus-like tissue injury, 6 h and 72 h after i.p. lipopolysaccharide (LPS; endotoxin) injection in pristane-primed chronic inflammation ICR mice characterized by a lupus-like syndrome. These results demonstrated that levels of serum IL-6, IL-10 and IFN-gamma and bronchoalveolar lavage (BAL) IL-6 and IFN-gamma were remarkably increased 6 h in LPS-exposed pristane-primed mice compared with pristane-primed controls, while pulmonary vascular permeability and levels of serum and BAL TNF-alpha were not. And levels of BAL TNF-alpha, IL-6 and IL-10 were significantly enhanced 72 h in LPS-exposed pristane-primed mice compared with pristane-primed controls. Also, LPS significantly induced the increased in vitro production of TNF-alpha, IL-6 and IL-10 by lung cells obtained from LPS-exposed pristane-primed mice compared with LPS-exposed normal mice. Our findings indicate that LPS may trigger persistent progression of lung injury through late overproduction of BAL TNF-alpha, IL-6, and IL-10 in lupus-like chronic inflammation syndrome compared with normal condition.     

The screening and isolation of an effective anti-endotoxin monomer from Radix Paeoniae Rubra using affinity biosensor technology

Lipopolysaccharide (LPS) is a known trigger in the pathogenesis of sepsis, lipid A being the toxic component. One of several adjuvant therapeutic approaches for severe sepsis is currently focusing on the neutralization of LPS. In order to obtain the components from traditional Chinese herbs that can neutralize the endotoxin, aqueous extractions were tested using affinity biosensor technology. From amongst 42 herbs, eight were found to possess lipid A-binding abilities. Radix Paeoniae Rubras had the highest lipid A-binding ability; therefore an aqueous extraction from this plant was investigated further. After preparation using standard methods, including silica gel chromatography and HPLC, we obtained 1, 2, 3, 4, 6-beta-d-pentagalloylglucose (PGG), with lipid A-binding ability. It was found that in vitro, PGG directly bound to lipid A, with a Kd of 32 microM, and that it neutralized the endotoxin both in the Limulus Amebocyte Lysate (LAL) assay and in a TNF-alpha release experiment, in a dose-dependent manner. In in vivo experiments, PGG was found to protect mice from a lethal challenge by LPS, and significantly decreased the plasma endotoxin level both in endotoxemic mice and rats, the reduction of the endotoxin level in rats being tightly associated with the TNF-alpha level. In conclusion, we demonstrate the effectiveness of affinity biosensor technology in discovering useful agents amongst traditional Chinese herbs and using this approach we found a new anti-endotoxin agent.     

Effects of post-treatment with low-dose propofol on inflammatory responses to lipopolysaccharide-induced shock in conscious rats

1. In the present study, we used a low dose of propofol (5 mg/kg per h) to investigate its effects on the pro-inflammatory cytokines (tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-10) and changes in nitric oxide (NO) following lipopolysaccharide (LPS) for a period of 12 h in conscious rats. 2. Experiments were designed to induce endotoxin shock by intravenous injection of Klebsiella pneumoniae LPS (10 mg/kg) in conscious rats. Arterial pressure (AP) and heart rate (HR) were monitored continuously for 12 h after LPS administration. Tumour necrosis factor-alpha, IL-1beta, IL-10 and plasma nitrates/nitrites were determined before and 0.5, 1, 3, 6, 9 and 12 h after LPS administration. A low dose of intravenous propofol (5 mg/kg per h) was administered to investigate the effects on cytokine responses and changes in NO in endotoxin shock. 3. Lipopolysaccharide significantly increased TNF-alpha, IL-1beta, IL-10, nitrites/nitrates and HR, whereas mean AP was decreased. Post-treatment with propofol suppressed the release of TNF-alpha, IL-1beta, IL-10 and NO production after endotoxin shock. 4. Lipopolysaccharide also caused a decrease in the white blood cell count and haematocrit. 5. Post-treatment with propofol slightly, but not significantly, affected the LPS-induced systemic hypotension, tachycardia, leukocytopenia and anaemia. 6. These findings suggest that low-dose propofol may be beneficial to the inflammatory change in sepsis.     

Anti-tumor necrosis factor agent PEG-sTNFRI improves the growth hormone/insulin-like growth factor-I system in adjuvant-induced arthritic rats

Adjuvant-induced arthritis is associated with body weight loss and decreased pituitary growth hormone (GH) and hepatic insulin-like growth factor-I (IGF-I) synthesis. Cytokines as tumor necrosis factor (TNF) mediate wasting associated with chronic inflammation. The aim of this study was to analyse whether the inhibition of TNF is able to revert the decrease in the body weight and the GH/IGF-I axis in arthritic rats. Male Wistar rats were injected with Freund's adjuvant, and 15 days later arthritic and control rats were daily injected with polyethylene glycol linked to soluble TNF receptor p55 (PEG-sTNFRI) (1 mg/kg, s.c.) or saline for 8 days. There was a significant decrease in pituitary GH mRNA (P<0.05), hepatic IGF-I mRNA (P<0.01) and serum concentrations of IGF-I (P<0.01) in arthritic rats. The 8-day administration of PEG-sTNFRI resulted in an increase in food intake (P<0.05) and body weight gain (P<0.01) in arthritic but not in control rats. There was an increase in pituitary GH mRNA after PEG-sTNFRI treatment both in control and in arthritic rats. There was a significant increase in IGF-I serum concentrations (P<0.05) and hepatic IGF-I mRNA expression (P<0.05) in control rats treated with PEG-sTNFRI, whereas the effect of this anti-TNF agent in arthritic rats was only statistically significant in hepatic IGF-I mRNA expression (P<0.05). These data suggest that TNF seems to be involved in the decrease in GH and IGF-I synthesis in arthritic rats.     

Neutral sulfate berberine modulates cytokine secretion and increases survival in endotoxemic mice

AIM: Berberine is thought to be an immunomodulator, so the present study aimed to investigate the effect of berberine on mortality, lung and intestine injury in endotoxemic mice, and the mechanism of its action. METHODS: Mice were challenged with lipopolysaccharide (LPS, 28 mg/kg, ip), and neutral sulfate berberine was administrated intragastrically. Mortality was monitored every 12 h, and histology of the lungs and intestine as well as the plasma tumor necrosis factor-alpha (TNF-alpha), interferon- gamma (IFN-gamma), interleukin-12 (IL-12), IL-10, and nitric oxide (NO) levels were examined. RESULTS: Pretreatment with 50 mg/kg neutral sulfate berberine once a day for 5 days significantly decreased the mortality rate and attenuated tissue injury of the lungs and small intestine in mice challenged with LPS. LPS stimulated a marked increase in plasma levels of TNF-alpha, IFN- gamma, IL-12, IL-10, and NO. The administration of berberine significantly reduced plasma TNF-alpha, IFN- gamma, and NO levels, but did not suppress plasma IL-12 levels in mice exposed to LPS. Furthermore, pretreatment with neutral sulfate berberine augmented IL-10 secretion stimulated by LPS in mice. CONCLUSION: Pretreatment with neutral sulfate berberine attenuates tissue injury and improves survival in endotoxemic mice, which may be mediated, at least in part, by the inhibition of pro-inflammatory mediator production and upregulation of IL-10 release. These findings might provide a new strategy for the treatment of endotoxemia.     

Cytokine-mediated induction of cyclo-oxygenase-2 by activation of tyrosine kinase in bovine endothelial cells stimulated by bacterial lipopolysaccharide.

1. The induction of cyclo-oxygenase-2 (COX-2) afforded by bacterial lipopolysaccharide (LPS, endotoxin) in bovine aortic endothelial cells (BAEC) is mediated by tyrosine kinase. LPS also causes the generation of several cytokines including interleukin-1 beta (IL-1 beta), tumour necrosis factor-alpha (TNF-alpha), epidermal growth factor (EGF) and platelet-derived growth factor (PDGF). This study investigates whether endogenous IL-1 beta, TNF-alpha, EGF or PDGF contribute to the induction of COX-2 elicited by LPS in BAEC and if their action is due to activation of tyrosine kinase. Furthermore, we have studied the induction of COX-2 by exogenous cytokines. 2. Accumulation of 6-oxo-prostaglandin (PG) F1 alpha in cultures of BAEC was measured by radioimmunoassay at 24 h after addition of either LPS (1 microgram ml-1) alone or LPS together with a polyclonal antibody to one of the various cytokines. In experiments designed to measure 'COX activity', 6-oxo-PGF1 alpha generated by BAEC activated with recombinant human IL-1 beta, TNF-alpha, EGF or PDGF for 12 h was measured after incubation of washed cells with exogenous arachidonic acid (30 microM for 15 min). Western blot analysis determined the expression of COX-2 protein in BAEC. 3. The accumulation of 6-oxo-PGF1 alpha caused by LPS in BAEC was attenuated by co-incubation with one of the polyclonal antibodies, anti-IL-1 beta, anti-TNF-alpha, anti-EGF, anti-PDGF or with the IL-1 receptor antagonist, in a dose-dependent manner. Exogenous IL-1 beta, TNF-alpha or EGF also caused an increase in COX activity, while PDGF was ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)