leukotriene-b4 and Uveitis

To investigate the role of leukotriene B4 (LTB4) and its receptor BLT1 in the pathogenesis of mouse uveitis.. Experimental autoimmune uveitis (EAU) was induced in B10RIII mice by immunization of interphotoreceptor retinoid binding protein (IRBP; peptide sequence 161-180) or in C57BL/6 (B6) mice by transfer of activated T cells specific for IRBP1-20. The animals were then treated with and without the BLT1 receptor antagonist, CP105696, at the disease onset after immunization or at day 0 or day 6 after T-cell transfer. EAU was also induced in wild-type B6 (WT) and BLT1-deficient (BLT1-/-) mice by reciprocal transfer of the T cells from B6 to BLT1-deficient mice and vise versa. Clinical signs of inflammation and ocular histology were compared. The chemotactic activity of LTB4 on naïve and IRBP-specific autoreactive T cells as well as effector leukocytes was examined.. The treatment of CP105696, greatly reduced the intensity of ongoing disease. IRBP1-20-specific T cells derived from wild-type B6 mice induced only mild uveitis in syngeneic BLT1-deficient mice and that IRBP1-20-specific T cells derived from BLT1-/- mice induced milder disease in wild-type B6 mice than those derived from wild-type B6 mice, suggesting that expression of the LTB4 receptor on both activated autoreactive T cells and effector leukocytes was necessary for ocular inflammation to occur. Consistent with these data, transfer of autoreactive T cells from B6 mice to 5-lipoxygenase-deficient (5-LO-/-) mice, which have a functional defect in LTB4 expression, also failed to induce uveitis in the recipient mice.. The results demonstrate a critical role for LTB4 in ocular inflammation and in the development and progression of EAU and suggest a new potential target for therapeutic intervention in this disease.

Topics: Adoptive Transfer; Animals; Arachidonate 5-Lipoxygenase; Autoimmune Diseases; Benzopyrans; Carboxylic Acids; Cells, Cultured; Chemotaxis, Leukocyte; Disease Models, Animal; Eye Proteins; Female; Immunization; Leukotriene B4; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Mice, Knockout; Peptide Fragments; Purinergic P2 Receptor Antagonists; Receptors, Leukotriene B4; Receptors, Purinergic P2; Retinol-Binding Proteins; T-Lymphocytes; Uveitis

We studied if tobramycin associated to sodium diclofenac modifies the drug effect of the latter on arachidonic acid metabolism in an endotoxin induced uveitis (EIU) model in albino rabbits.. Experimental uveitis was induced by intravitreal injection of a 10 ng lipopolysaccharide A Salmonella typhimurium endotoxin dissolved in 5 microl saline solution in the right eye of experimental animals. We have used 48 animals (4 groups of 12 animals each). The control group (G-I) was injected with saline solution (5 microl); the endotoxin group (G-II) was injected with 5 microl of ET; group III and IV were injected with the same amount of ET and treated with topical sodium diclofenac (1%) (Group III) and tobramycin and sodium diclofenac (0.3%) (Group IV) two hours before the administration of endotoxin and then every two hours until 24 hours, when we determined E2 prostaglandin and B4 leukotriene concentration in aqueous humor obtained by paracentesis of the anterior chamber.. We observed how the E2 prostaglandin concentration was reduced in the two treatment groups compared with the endotoxin group (p<0.01). However, there were no differences between groups III and IV (p>0.01). There was a mild increase of B4 leukotriene in both treatment groups, which was not significant in relationship to the endotoxin group (p>0.01). No differences were found between the two treatment groups (p>0.01).. Using the association of tobramycin does not affect the action of sodium diclofenac in arachidonic acid metabolism in endotoxin induced uveitis.

Topics: Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents, Non-Steroidal; Aqueous Humor; Bacterial Toxins; Diclofenac; Dinoprostone; Drug Interactions; Drug Therapy, Combination; Endotoxins; Leukotriene B4; Rabbits; Tobramycin; Uveitis

Nitric oxide (NO) synthase inhibitors, such as NG-nitro-L-arginine methyl ester (L-NAME), have been shown to attenuate endotoxin-induced uveitis (EIU) but they could increase leukocyte adhesion to the vascular endothelium. We hypothesize that a concomitant treatment with the 5-lipoxygenase inhibitor nordihydroguaiaretic acid (NDGA) in 50% dimethylsulfoxide (DMSO, a hydroxyl radical scavenger) could improve the anti-inflammatory activity of L-NAME. EIU was induced in albino rabbits by intravitreal injection of 100 ng lipopolysaccharide. Animals were treated with multiple intraperitoneal injections of 50% DMSO in phosphate-buffered saline (PBS), NDGA (10 mg/kg) in 50% DMSO, L-NAME (50 mg/ kg) in PBS, or the combination NDGA+L-NAME. Uveitis was assessed by slit lamp examination, protein levels in aqueous humor, and myeloperoxidase (MPO) activity in the iris/ciliary body 6 h after induction. Nitrite, leukotriene B4 (LTB4), prostaglandin E2 (PGE2), platelet-activating factor (PAF) and interleukin-1 beta (IL-1 beta) levels in aqueous humor were also determined. NDGA or L-NAME alone did not show a significant reduction of uveitis intensity, although a significant decrease in MPO or in proteins was found, respectively. The combination NDGA+L-NAME significantly reduced the uveitis intensity, MPO in the iris/ciliary body, and the levels of nitrites, LTB4, PGE2, and PAF in aqueous humor. IL-1 beta levels were lower than the detection limit of the radioimmunoassay in all treatment groups. We conclude that concomitant treatment with NDGA in DMSO improves the anti-inflammatory activity of L-NAME during the early phase of EIU, suggesting that the inhibition of NO synthesis could enhance leukocyte infiltration and the release of oxygen free radicals.

Topics: Administration, Topical; Animals; Anti-Inflammatory Agents; Aqueous Humor; Ciliary Body; Dimethyl Sulfoxide; Dinoprostone; Disease Models, Animal; Drug Therapy, Combination; Endothelium, Vascular; Endotoxins; Enzyme Inhibitors; Interleukin-1; Iris; Leukotriene B4; Lipoxygenase Inhibitors; Male; Masoprocol; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase; Peroxidase; Rabbits; Salmonella typhimurium; Treatment Outcome; Uveitis

The effect of rabbit vitreous with endotoxin-induced uveitis was investigated for its role in the modulation of rat corneal neovascularization (NV). Elvax pellets implanted into at cornea contained either uveitic vitreous, intact vitreous or Elvax alone. The latter two kinds of pellets did not elicit NV. Uveitic vitreous pellets caused, in 100% of eyes, a persistent NV with maximal growth on the 10th day post implantation. Prostaglandin E2 and leukotriene B4 levels in the uveitic rabbit vitreous at 36 h postendotoxin injection were 7- and 5-fold higher than baseline, respectively. Histopathologically, the neovascularized cornea showed a significant inflammatory reaction attributable to the uveitic vitreous extract.

Topics: Animals; Cornea; Corneal Neovascularization; Dinoprostone; Drug Implants; Endotoxins; Escherichia coli; Female; Keratitis; Leukotriene B4; Male; Polyvinyls; Rabbits; Uveitis; Vitreous Body

Recombinant human interleukin-1 alpha, interleukin-1 beta (10, 80 or 200 units), interleukin-8 (10 or 40 units) or endotoxin was injected intravitreally into rabbit eyes. Twenty-four hours thereafter aqueous humor protein, leukocyte number, prostaglandin E2, leukotriene B4 and rabbit interleukin-1 beta were measured. In addition, synthesis of prostaglandin E2 and leukotriene B4 in iris-ciliary body and myeloperoxidase (MPO) activity were determined. Recombinant human interleukins 1 alpha and 1 beta, but not interleukin-8 induced signs of uveitis, i.e. protein and leukocytic infiltration into aqueous humor. At 200 unit activities, human interleukin-1 beta was significantly greater than interleukin-1 alpha in causing leukocyte infiltration response. Interleukin-1 alpha did not stimulate the release of prostaglandin E2 or leukotriene B4. In fact, interleukin-1 beta significantly inhibited the synthesis of prostaglandin E2 in iris-ciliary body. Both of these human interleukins caused a release of rabbit interleukin-1 beta in aqueous achieving a level significantly higher than observed after endotoxin injection. This study demonstrates that intravitreal injections of human IL-1 alpha and IL-1 beta induce uveitis by releasing rabbit interleukin-1 beta within the eye.

Topics: Animals; Aqueous Humor; Chemotaxis, Leukocyte; Ciliary Body; Dinoprostone; Endotoxins; Interleukin-1; Interleukins; Iris; Leukocyte Count; Leukotriene B4; Male; Peroxidase; Rabbits; Recombinant Proteins; Uveitis

The effects of cyclooxygenase inhibitors flurbiprofen and indomethacin on the inflammatory response and immune reactions induced by S-antigen in the rat eye were studied. The treatment with flurbiprofen and indomethacin administered subcutaneously every 12 hours, commenced on the day of S-antigen injection and was continued until the termination of the experiment (12 days). Flurbiprofen reduced vasodilation and the inflammatory exudate into the anterior chamber by 38% and 36% respectively while inhibiting polymorphonuclear leukocytes infiltration by 57% without affecting monocytes infiltration. Indomethacin had similar but greater effects than flurbiprofen on all these parameters. However, the differences between the mean values of the two compounds were not significant. Both compounds also attenuated spleen cell proliferation, serum IgG levels to S-antigen and interferon-gamma levels in the aqueous humor. The level of prostaglandin E2, but not of leukotriene B4, was increased in the untreated inflamed uveal tissues and this increase was significantly inhibited by flurbiprofen and indomethacin. The results of this study suggest that cyclooxygenase products are involved in the normal development of both humoral and cellular immune response in the experimental uveitis.

Topics: Animals; Antigens; Arrestin; Autoantibodies; Dinoprostone; Disease Models, Animal; Eye Proteins; Female; Flurbiprofen; Immunoglobulin G; Indomethacin; Injections, Subcutaneous; Leukotriene B4; Membrane Proteins; Neutrophils; Phosphodiesterase Inhibitors; Rats; Rats, Inbred Lew; Uveitis

Dogs were treated with flunixin meglumine, a cyclooxygenase inhibitor; L-651,896, a 5-lipoxygenase inhibitor; and matrine, a herbal anti-inflammatory drug. Acute inflammation was induced in the eyes by disruption of the anterior lens capsule, using a neodymium:yttrium aluminum garnet laser. Intraocular pressure, pupil diameter, and eicosanoid production in the aqueous humor were measured. Statistically significant effects were seen in the eyes of flunixin meglumine-treated dogs where mydriasis was maintained and aqueous prostaglandin E2 concentration was reduced.

Topics: Alkaloids; Animals; Anti-Inflammatory Agents, Non-Steroidal; Aqueous Humor; Benzofurans; Clonixin; Dinoprostone; Dog Diseases; Dogs; Intraocular Pressure; Laser Therapy; Leukotriene B4; Lipoxygenase Inhibitors; Matrines; Pupil; Quinolizines; Uveitis

The anti-inflammatory effects of vitamin E were investigated using the S antigen model of uveoretinitis. Thirty-six 3-week-old Lewis rats were separated into three groups and maintained on a specially formulated diet. One group of animals received a diet deficient in vitamin E; a second group received a normal diet containing vitamin E, and the third group, in addition to receiving the normal diet, received vitamin E supplementation. At 9 weeks of age, all rats were sensitized to S antigen. Six animals in each group were killed on day 14 and the remaining animals on day 21 following immunization. Both histopathologic and biochemical studies were conducted to evaluate the tissue damage observed in animals maintained on different dietary levels of the vitamin. The intraocular inflammation in the vitamin E-supplemented group was considerably smaller than in the other two groups (p less than 0.01). The former group had the highest level of vitamin E in both the eye and plasma (mean value 1.13 micrograms/mg protein and 23.9 micrograms/ml, respectively), while the vitamin E-deficient group had the lowest levels (mean values of 0.16 micrograms/mg protein and 0.48 micrograms/ml in the eye and plasma, respectively). Results of the radioimmunoassay for the determination of the arachidonic acid metabolites revealed significantly lower levels of thromboxane B2 in the vitamin E-supplemented group (2.04 +/- 0.45 pg/mg) than in the normal (4.33 +/- 0.98 pg/mg) or the vitamin E-deficient (5.21 +/- 1.12 pg/mg) groups (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Antigens; Arrestin; Autoantigens; Choroid; Diet; Dinoprostone; Disease Models, Animal; Eye Proteins; Female; Leukotriene B4; Membrane Proteins; Phosphodiesterase Inhibitors; Radioimmunoassay; Rats; Rats, Inbred Lew; Retinitis; Thromboxane B2; Uveitis; Vitamin E

The role of endogenously released eicosanoids in intraocular inflammation was assessed in two rabbit models. The models were: (1) paracentesis in which only breakdown of blood-aqueous barrier (BAB) occurs and (2) uveitis induced by endotoxin in which the disruption of the BAB and polymorphonuclear leukocyte infiltration are the predominant events. Indomethacin (a specific cyclooxygenase inhibitor) applied topically inhibited both the disruption of the BAB and increased levels of aqueous humor 6-keto-Prostaglandin (PG)F1 alpha. However, indomethacin and flurbiprofen applied topically and BWA4C or BWA218C (both selective lipoxygenase inhibitors) given parenterally, did not inhibit BAB response in endotoxin-induced uveitis. The cyclooxygenase inhibitors attenuated PGE2 release into aqueous humor. The 5-lipoxygenase inhibitors reduced the PMN infiltration as well as LTB4 release into aqueous humor. However, myeloperoxidase activity (an index for PMN chemotaxis) in iris-ciliary body was not affected by these drugs. Furthermore, concentrations of LTB4 in aqueous humor after paracentesis and uveitis-induced by endotoxin were similar, although in the former model there was no leukocyte infiltration, but in the latter model this leukocyte response was predominant. The results of this study suggest that locally released autocoids may not initiate ocular inflammation and other mediators such as cytokines may be involved in the inflammatory responses of the rabbit eye. We tried to detect IL-1 activity in aqueous humor following endotoxin. However, we could not detect the presence of IL-1-like activity, possibly because endotoxin also releases PGs, which inhibit IL-1 bioassay.

Topics: Animals; Aqueous Humor; Biological Transport, Active; Blood; Ciliary Body; Cyclooxygenase Inhibitors; Dinoprostone; Disease Models, Animal; Endotoxins; Escherichia coli; Interleukin-1; Iris; Leukocyte Count; Leukotriene B4; Lipoxygenase Inhibitors; Male; Peroxidase; Rabbits; Uveitis

Endotoxin-induced uveitis (EIU) can be produced by systemic injection of endotoxin (ET). It is not clear yet why exclusive ocular involvement occurs in this model. To clarify this question and to establish the sequence of inflammatory events, EIU was induced in Lewis rats by footpad injection of Salmonella ET. Ocular inflammatory response (anterior chamber cells and proteins), aqueous inflammation mediators (thromboxane B2, prostaglandin E2, leukotriene B4 and substance P) and MHC class 2 (Ia) antigen expression in the ciliary body were monitored for 72 hours. Thromboxane B2 was detected early in the aqueous humor, peaking already 1 hour after ET injection. Prostaglandin E2 & leukotriene B4 peaks and a second peak of thromboxane B2 were recorded 18 hours after ET-injection, at the time of maximal ocular inflammation. MHC-class 2 expression was first detected in the ciliary body stroma at the vascular level 6 hours after ET injection and was massively expressed in the ciliary body epithelium at 18 and 72 hours. It is hypothesized that ciliary body endothelium is particularly sensitive to the effect of ET and is the site of thrombocyte adherence. Vascular damage leads in succession to cellular infiltration, release of inflammation mediators and disruption of blood-ocular barrier. MHC-class 2 expression is a secondary phenomenon and is probably at the origin of additional tissue damage from immune effector mechanisms.

Topics: Animals; Aqueous Humor; Bacterial Toxins; Cell Count; Ciliary Body; Dinoprostone; Endotoxins; Enterotoxins; Eye Proteins; Histocompatibility Antigens Class II; Inflammation; Leukotriene B4; Male; Rats; Rats, Inbred Lew; Substance P; Thromboxane B2; Uveitis

Systemic injection of bacterial endotoxin (Lipopolysaccharide, LPS) in experimental animals induces anterior uveitis without major pathological changes in other organs. The present study investigates the effect of LPS on production of inflammatory mediators in cultured bovine pigmented ciliary epithelial cells (CB-cells) by means of radioimmunoassays and bioassays. LPS was found to stimulate CB-cells to secrete prostaglandin E2 and prostacyclin (assayed as its stable metabolite 6-keto-prostaglandin F1a), but not leukotriene B4 or thromboxane A2 (assayed as its stable metabolite thromboxane B2). CB-cells produced membrane-associated interleukin 1-activity in response to LPS, but no tumor necrosis factor-activity was found after challenge of CB-cells with LPS. The direct effect of LPS on production of inflammatory mediators by cells from the anterior uvea could play a role in the pathophysiology of endotoxin-induced uveitis.

Topics: Animals; Cattle; Cells, Cultured; Ciliary Body; Dinoprostone; Epithelium; Epoprostenol; Inflammation; Interleukin-1; Leukotriene B4; Lipopolysaccharides; Radioimmunoassay; Thromboxane A2; Tumor Necrosis Factor-alpha; Uveitis

Footpad injection of endotoxin causes exclusive ocular inflammation in the rat. In order to clarify its physiopathologic mechanism, we studied the effect of different treatments on endotoxin-induced uveitis (EIU). Salmonella endotoxin was injected into the footpads of Lewis rats. 18 hr later, inflammation was assessed by evaluating proteins and cells in the anterior chamber; arachidonic acid (AA) metabolites, prostaglandin E2 and leukotriene B4, as well as substance P were measured by radioimmunoassay, and Ia-(MHC class II)-antigen expression in ciliary body was assessed by immunohistochemistry. The effect of inhibitors of phospholipase A2 (EPC), of lipoxygenase (azelastine) and of cyclo-oxygenase (diclofenac), as well as dexamethasone, cyclosporine (CsA) and anti-Ia antibody, were evaluated on these parameters. Phospholipase A2 inhibitor EPC and dexamethasone were most effective on inflammation: they also reduced AA metabolites very effectively and prevented Ia-expression. Lipoxygenase and cyclo-oxygenase inhibitors were partially effective on inflammation and on AA metabolites but failed to prevent Ia-expression. Immunosuppressive treatments (CsA and anti-Ia-antibody) also reduced inflammation. Our findings suggest that inflammation mediators initiate inflammation in EIU. Ia-Ag-expression is secondarily produced by mediators leading to additional inflammation due to immune mediated mechanisms.

Topics: Animals; Aqueous Humor; Ciliary Body; Dinoprostone; Endotoxins; Eye Proteins; Histocompatibility Antigens Class II; Leukotriene B4; Male; Rats; Rats, Inbred Lew; Salmonella; Uveitis

Intraocular inflammation was induced in the rat by footpad injection of salmonella endotoxin in order to study the influence of chemical inflammation mediators in this uveitis model. Ocular inflammation was assessed 1, 6, 18, 24 and 72 h after endotoxin administration as well as in control rats, by measuring aqueous protein concentration, aqueous inflammatory cell content, and pupillary diameter. Thromboxane B2 (TXB2), prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2-alpha), leukotriene B4 (LTB4), and substance P were simultaneously measured in the aqueous humor by radioimmunoassay. Inflammation parameters peaked at 18 h. TXB2 was already significantly elevated at 1 h. PGE2 peak values of 2.7 ng/ml were reached at 18 h. PGF2-alpha was never significantly raised over control values. LTB4 peaked at 18 h, together with a polymorphonuclear peak. Substance P was significantly elevated after 6 h. It is concluded that maximal uveitis in this model occurs at 18 h. TXB2 is an early mediator, and PGE2 is probably implicated in blood-ocular barrier disruption for which levels as high as 2.7 ng/ml in aqueous seem necessary. PGF2-alpha does not play a major role in this model, while LTB4 seems to be the main chemotactic factor for polymorphonuclears (PMNs) in the anterior chamber and substance P is clearly related to pupil miosis.

Topics: Animals; Aqueous Humor; Dinoprost; Dinoprostone; Endotoxins; Leukotriene B4; Male; Pupil; Rats; Rats, Inbred Lew; Salmonella; Substance P; Thromboxane B2; Uveitis

Topics: Animals; Aqueous Humor; Chemotaxis, Leukocyte; Dose-Response Relationship, Drug; Leukotriene B4; Neutrophils; Rabbits; Tumor Necrosis Factor-alpha; Uveitis

Topics: Aged; Animals; Aqueous Humor; Female; Humans; Iris; Leukotriene B4; Male; Middle Aged; Rabbits; Uveitis

Inflammation induced by systemic injection of endotoxin can be a good model for endogenous uveitis since ocular inflammation is induced without manipulating the eye. We carried out morphological and biochemical studies in Lewis rats to evaluate the breakdown of the blood-ocular barrier following injection of endotoxin (1 mg/rat) in footpads. Vasodilation was observed as early as 3 hours and became maximum at 18-24 hours after the injection. Unlike in the eye, no inflammatory changes were observed in other organs. Protein and cell contents in the aqueous humor increased significantly as early as 3 hours after the injection and reached a peak level at 24 hours. The protein content returned to the normal level in the following several days, while cells in the aqueous humor remained at a high level even 1 week after the injection. The time-course of the pupillary size was very similar to that of the protein concentration. Furthermore, we examined leukotrienes (LTs) levels in aqueous humor by high-pressure liquid chromatography. LTD4 was detected in the aqueous humor at 6 hours and reached its peak level at 24 hours. The present data indicates that the systemic injection of endotoxin causes the disruption of the blood-ocular barrier soon after the injection and inflammation becomes maximum in 18-24 hours. This model can be used for studying endogenous uveitis and the disruption of the blood-ocular barrier without direct trauma to the eye.

Topics: Animals; Aqueous Humor; Chromatography, High Pressure Liquid; Disease Models, Animal; Dose-Response Relationship, Immunologic; Endotoxins; Injections; Leukotriene B4; Male; Rats; Rats, Inbred Lew; Retina; Shigella flexneri; Time Factors; Uveitis; Uveitis, Anterior

Topics: Aqueous Humor; Humans; Leukotriene B4; Uveitis

Utilizing chromatographic and radioimmunoassay techniques, we measured the concentration of leukotriene (LT) B4 and LTC4/D4/E4 in the aqueous humor of 14 patients with uveitis and seven patients undergoing penetrating keratoplasty or routine cataract extraction. Leukotriene B4 was detected in 11 of 14 patients with uveitis (mean, 0.96 pmole/mL), and LTC4/D4/E4 was found in 12 of 14 patients with uveitis (mean, 2.0 pmole/mL). In the control group, LTB4 was detected in six of seven patients (mean, 0.57 pmole/mL), and LTC4/D4/E4 was found in six of seven patients (mean, 1.9 pmole/mL). Leukotriene levels did not correlate with clinically assessed aqueous cell and flare. Mean levels of LT in patients with uveitis receiving corticosteroids were nearly double those found in non-steroid-treated patients. Despite apparent differences in LT levels, none of the above differences reached statistical significance.

Topics: Adrenal Cortex Hormones; Aqueous Humor; Chromatography; Humans; Leukotriene B4; Leukotriene E4; Radioimmunoassay; SRS-A; Uveitis