Volatile Sulfur Compounds Produced by the Anaerobic Bacteria Porphyromonas spp. Isolated from the Oral Cavities of Dogs.

Porphyromonas spp. are oral anaerobic Gram-negative bacteria that form black-pigmented colonies on blood agar and produce volatile sulfur compounds (VSCs), such as hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl sulfide ((CH3)2S), which cause halitosis and the destruction of periodontal tissues. P. gulae is considered the main pathogen involved in periodontal disease in dogs. However, the characteristics of the VSCs produced by P. gulae are unknown. In the present study, VSCs were measured in 26 isolates of P. gulae and some isolates of the other Porphyromonas spp. obtained from the oral cavities of dogs with periodontal disease using an in vitro assay with an Oral ChromaTM gas chromatograph. The results demonstrated that P. gulae was able to produce large amounts of H2S and CH3SH, and the dominant product was CH3SH (CH3SH/H2S was approximately 2.2). Other Porphyromonas spp. that were also obtained from the oral cavities of dogs with periodontal disease indicated similar levels of production of H2S and CH3SH to those of P. gulae. It is strongly suggested that the high levels of H2S and CH3SH produced by P. gulae and other Porphyromonas spp. contribute to halitosis and the destruction of periodontal tissues during the progression of periodontal disease in dogs.

Perception biases for problematic behaviors in dogs due to owners' attributes.

The abnormal or undesirable behaviors of owned dogs are not always considered problematic; it depends on the perception bias of their owners. To demonstrate the perception bias in dog owners' attributes, 133 dog owners in Aomori (rural) and Tokyo (urban) were surveyed through questionnaires distributed via seven animal hospitals regarding the frequency of potentially problematic behaviors and their perceived difficulty with them. The interaction effects of the lived location (urban, rural), age (20s-50s, 60s or later), and sex (male, female) of the owners were evaluated through a hierarchical multiple regression model. The analyses of 115 responses demonstrated that the tendency of perception regarding the five major behaviors under consideration varied with these attributes. Our results indicated that owners living in Aomori undervalued destruction behaviors of their dogs both when family members were and were not at home, while they overvalued jumping on people. Senior owners tended to undervalue nuisance barking when family members were at home along with uncontrollable hyperactivity. Male owners also undervalued destructive behavior when family members were not home. The study concludes that perception bias due to dog owners' attributes should be taken into account in epidemiological surveys and during medical interviews by veterinarians or other behavioral specialists. Further exhaustive investigation and exploration of the cultural background of these perception differences should be conducted.

Effects of a Soluble Guanylate Cyclase Stimulator Riociguat on Contractility of Isolated Pulmonary Artery and Hemodynamics of U46619-Induced Pulmonary Hypertension in Dogs.

Soluble guanylate cyclase (sGC) stimulator riociguat is a relatively novel therapeutic agent for pulmonary hypertension (PH) in human medicine. Riociguat induces endothelium-independent pulmonary artery (PA) relaxation by directly activating the sGC-cyclic guanosine-3',5'-monophosphate (cGMP) pathway in muscle cells. Although riociguat may be effective in the treatment of dogs with refractory PH, basic studies on its clinical application in veterinary medicine are lacking. The present study aimed to explore the effects of riociguat on the contractility of an isolated canine PA and the hemodynamics of dogs with acute PH. In an isolated endothelium-denuded canine PA, the effects of riociguat on endothelin (ET)-1-induced contraction and cGMP levels were investigated using the Magnus method and ELISA, respectively. The effect of riociguat on the hemodynamics of the thromboxane A2 analog U46619-induced PH model dog was examined by invasive catheterization. Riociguat increased cGMP levels and reduced ET-1-induced contraction of the isolated PA. Riociguat inhibited the U46619-induced elevation of PA pressure and pulmonary vascular resistance and increased cardiac output, but it had no effect on basal systemic blood pressure. These results demonstrate for the first time that riociguat can inhibit the elevation of PA pressure through PA relaxation via an endothelium-independent increase in cGMP in dogs with PH.

Molecular prevalence and zoonotic potential of trichomonads from oral cavities in household dogs.

This study investigated the molecular prevalence of oral trichomonads in household dogs. Of the 144 dogs, 21 (14.6%, 21/144) tested positive for oral trichomonads. The prevalence was significantly higher in dogs with severe gingivitis (gingival index 3: 30.0%, 8/26) than that in normal dogs (gingival index 0: 2.7%, 1/37). Therefore, an interaction between oral trichomonads and the development of periodontal disease is suggested. Of the 21 positive samples, 16 isolates were T. brixi, four isolates were T. tenax, and one was Tetratrichomonas sp. Considering T. tenax is recognized as a zoonotic agent, transmission between dogs and humans cannot be neglected.

Molecular Identification of Encephalitozoon hellem from Companion Birds Kept in Pet Shops, Japan.

To evaluate the role of companion birds as a reservoir of Encephalitozoon hellem infection in humans, the present study determined the prevalence and genotypes of E. hellem from 269 birds in 4 pet shops using polymerase chain reaction (PCR) assay. E. hellem was identified in 4.8% (13/269) of the birds and was detected in all pet shops. Every positive sample corresponded to zoonotic genotype 1A. Considering the low prevalence of E. hellem infection, it is likely that the risk of zoonotic transmission from companion birds kept in pet shops to humans is low in Japan.

Molecular prevalence of trichomonad species from pet shop puppies and kittens in Japan.

Pentatrichomonas hominis and Tritrichomonas foetus (cat genotype) have been commonly identified as intestinal trichomonads in both dogs and cats. Although P. hominis is considered as non-pathogenic protozoa in many kinds of mammals, it has the potential for zoonotic transmission. T. foetus has been recognized as the emerging causative agent of diarrhea in cats without the risk of zoonotic transmission. As pet shops are the major source of young companion animals, the present study discusses the molecular prevalence of P. hominis and T. foetus from 544 pet shop puppies and 409 kittens. The results suggest that the prevalence of P. hominis (puppies: 7.0%; kittens: 0.5%) and T. foetus (puppies: 0%; kittens: 2.4%) in pet shop young animals are low. In addition, the infections of P. hominis and T. foetus are not always associated with the clinical signs (soft or diarrhea feces).

Clinical efficacy of combination therapy of itraconazole and prednisolone for treating effusive feline infectious peritonitis.

A 3-month-old male Scottish Fold kitten with pleural fluid and low ratio of albumin to globulin (A/G ratio) was brought to our small animal hospital. Since RNA from the type I feline coronavirus (FCoV) were detected in drained pleural fluid, the cat was tentatively diagnosed with effusive feline infectious peritonitis (FIP). Following the administration of itraconazole and prednisolone, the A/G ratio increased, and the pleural fluid mostly disappeared. The fecal FCoV levels temporarily decreased. However, the cat showed neurological manifestations and was eventually euthanized due to status epilepticus after 38 days of treatment. In conclusion, itraconazole partly exerted a beneficial effect in a cat with FIP. However, further investigation of a possible role of itraconazole in FIP treatment is warranted.

A case of canine hypoadrenocorticism needing blood transfusion for severe acute anemia due to gastrointestinal hemorrhage.

A 3-year-old male Rottweiler presented with the chief complaint of recurrent vomiting, diarrhea, hypothermia, and lethargy. Hypovolemic shock was noted with abnormal electrolytes (Na/K ratio, 27.9) and anemia (hematocrit, 17.3%). Since the hematocrit was 49.2% four days earlier when the primary veterinarian examined the dog, acute anemia was diagnosed. Melena was observed on the next day. The general condition and hydration improved with treatment, and an adrenocorticotropic hormone stimulation test identified hypoadrenocorticism. However, the hematocrit decreased further to 9%, necessitating blood transfusion. The cause of severe acute anemia was thought to be gastrointestinal hemorrhage. It should be noted that hypoadrenocorticism can lead to potentially fatal anemia with gastrointestinal tract bleeding, and blood transfusion may be required.

Molecular prevalence of trichomonad species from pet shop puppies and kittens in Japan / Molecular prevalência de espécies trichomonas em filhotes de cães e gatos de pet shop no Japão

Abstract Pentatrichomonas hominis and Tritrichomonas foetus (cat genotype) have been commonly identified as intestinal trichomonads in both dogs and cats. Although P. hominis is considered as non-pathogenic protozoa in many kinds of mammals, it has the potential for zoonotic transmission. T. foetus has been recognized as the emerging causative agent of diarrhea in cats without the risk of zoonotic transmission. As pet shops are the major source of young companion animals, the present study discusses the molecular prevalence of P. hominis and T. foetus from 544 pet shop puppies and 409 kittens. The results suggest that the prevalence of P. hominis (puppies: 7.0%; kittens: 0.5%) and T. foetus (puppies: 0%; kittens: 2.4%) in pet shop young animals are low. In addition, the infections of P. hominis and T. foetus are not always associated with the clinical signs (soft or diarrhea feces).

Resumo Pentatrichomonas hominis e Tritrichomonas foetus (genótipo de gato) têm sido comumente identificados como trichomonas intestinais em cães e gatos. Apesar de P. hominis ser considerado como protozoário não patogênico em muitos tipos de mamíferos, tem potencial para transmissão zoonótica. Enquanto o T. fetus foi reconhecido como o agente causador emergente de diarreia em gatos sem o risco de transmissão zoonótica. Devido às lojas de animais serem as principais fontes de filhotes de animais domésticos, o presente estudo discute a prevalência molecular e/ou o potencial zoonótico de P. hominis e T. foetus em 544 filhotes de cachorro e 409 gatos de "pet shop". Os resultados sugerem que a prevalência de P. hominis (cães: 7,0%; gatos: 0,5%) e T. foetus (cães: 0%; gatos: 2,4%) em animais jovens de "pet shop" é baixa. Além disso, as infecções de P. hominis e T. foetus nem sempre estão associadas aos sinais clínicos (fezes moles ou diarreia).

Molecular Prevalence of Cryptosporidium spp. in Breeding Kennel Dogs.

Cryptosporidium is a common intestinal protozoan that can lead to diarrhea in humans and dogs. The predominant species of infection are C. hominis and C. parvum in humans, and C. canis in dogs. However, C. canis can infect immunocompromised humans. Considering the close contact with humans, dogs have the potential to be reservoirs for human cryptosporidiosis. Breeding kennels are the major supply source of puppies for pet shops. The present study is to determine the molecular prevalence and characteristics of Cryptosporidium spp. found in breeding kennel dogs. A total of 314 fecal samples were collected from young and adult dogs kept in 5 breeding kennels. A polymerase chain reaction targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. To determine the species, the DNA sequences were compared to GenBank data. Overall, 21.0% of the fecal samples were positive for Cryptosporidium spp. infection. Cryptosporidium spp. was detected in all 5 facilities. A sequencing analysis demonstrated that all isolates shared 99-100% similarity with C. canis. The results suggest that Cryptosporidium spp. infection is present at a high-level in breeding kennel dogs. However, because dominant species in this survey was C. canis, the importance of breeding kennel dogs as reservoirs for Cryptosporidium spp. transmission to humans is likely to be low in Japan.

Molecular detection and genotyping of Enterocytozoon bieneusi in family pet dogs obtained from different routes in Japan.

The present study determined the prevalence of Enterocytozoon (E.) bieneusi infection and genotyped the isolates in family pet dogs obtained from three different routes in Japan. Fresh fecal samples were collected from 597 family pet dogs. A nested polymerase chain reaction (PCR) assay targeting the internal transcribed spacer (ITS) region of ribosomal DNA was employed for detection of E. bieneusi, and the obtained positive PCR amplicons were sequenced for genotyping. The overall prevalence of E. bieneusi in family pet dogs was 4.4%. Significant differences in prevalence were found among the categories of age (<1 year: 8.3% vs. ≥1 year: 3.4%), obtained route (from private owner: 3.2% vs. from pet shop: 3.9% vs. from breeding kennel: 14.3%), and living regions (ranged 0-10.3%). However, no significant differences were observed in the prevalence of living condition (indoor: 4.6% vs. outdoor: 2.0%), and fecal condition (formed: 4.5% vs. soft: 4.7% vs. diarrhea: 0%). Of the 26 sequenced samples, all were identified as genotype PtEb IX, which belongs to the dog-specific genotype. In conclusion, although E. bieneusi infections are relatively common in family pet dogs in Japan, the risk of zoonotic transmission from dogs to humans is likely to be low.

Molecular Prevalence of Cryptosporidium spp. among Companion Birds Kept in Pet Shops in Japan.

Cryptosporidium is the most common protozoan that can infect a wide range of animals, including mammals and birds. Avian Cryptosporidium spp. can cause enteric and respiratory diseases which can be fatal in birds and some species are zoonotic. Companion birds have the potential as reservoir due to their close contact with humans. Pet shops are the major source of companion birds. However, few reports are available regarding Cryptosporidium spp. infection among companion birds kept in pet shops. The present study reports the prevalence and molecular characteristics of Cryptosporidium spp. among companion birds kept in pet shops in Japan. A total of 265 fresh fecal samples were obtained from birds kept in 4 pet shops; these birds belonged to 41 species in 3 bird orders. A nested polymerase chain reaction (PCR) assay targeting the small subunit rRNA gene was employed for the detection of Cryptosporidium spp. A total of 24 samples (9.1%) were positive, and Cryptosporidium spp. were detected from all pet shops. The prevalence of Cryptosporidium spp. in each of the bird orders was 6.5% (10/153) in Psittaciformes, 14.4% (13/90) in Passeriformes, and 4.5% (1/22) in Galliformes. Based on sequence analysis, 13 (54.2%) isolates were classified to C. galli, 8 (33.3%) were avian genotype III, and the remaining 3 (12.5%) were C. baileyi. No infection with zoonotic C. meleagridis and no coinfection with multiple Cryptosporidium spp. and/or genotypes were observed. The zoonotic potential of Cryptosporidium spp. infecting companion birds kept in pet shops in Japan is likely to be low.

Multilocus genotyping of Giardia duodenalis isolates from household cats and pet shop kittens.

Giardia duodenalis is a pathogenic protozoan that causes diarrhea in mammalian hosts including humans and companion animals, and the host specificity differs depending on the genetic assemblages. The purpose of the present study is to perform multilocus genotyping at four loci of G. duodenalis isolates from household cats and pet shop kittens in Japan and evaluate the zoonotic potential. Fifty-seven fecal samples from cats (household cats: 13, pet shop kittens: 44), which were positive for Giardia-specific antigen as determined by an ELISA kit, were the subjects of our analysis. Nested or semi-nested PCRs targeting 18S ribosomal RNA (18S rRNA), glutamate dehydrogenase (GDH), beta-giardin (BG), and triosephosphate isomerase (TPI) were performed on all samples. All DNA amplicons were sequenced for genotyping. Forty-four isolates (household cats: 11, pet shop kittens: 33) were positive for at least one of the PCRs. Assemblage F was the most frequently detected (75%; 33/44), followed by assemblage A (13.6%; 6/44) and assemblage B (2.3%; 1/44). Four isolates (9.1%) showed the results as mixed assemblages F and A. Sub-genotyping of assemblage A isolates based on three loci (GDH, BG, and TPI) identified all of them as assemblage AI. DNA sequences of zoonotic G. duodenalis assemblages were detected from 25% of the genotyped specimens, and these were found at several shops and hospitals in Japan, which suggests that zoonotic G. duodenalis is prevalent among domestic cats in Japan, and that the considerable risk of zoonotic transmission of G. duodenalis from household cats or pet shop kittens to humans exists.

Multilocus genotyping of Giardia duodenalis isolates from breeding cattery cats in Japan.

OBJECTIVES: The present study reports the multilocus genotyping of Giardia duodenalis isolates from cats maintained in breeding catteries in Japan and discusses their potential for zoonotic transmission. METHODS: A total of 41 faecal samples positive for Giardia-specific antigen were procured from cats maintained in five breeding catteries and subjected to PCR to amplify four gene loci, namely small subunit ribosomal RNA (SSU rRNA), glutamate dehydrogenase (gdh), beta-giardin (bg) and triose phosphate isomerase (tpi ). The PCR-amplified DNA fragments were sequenced to determine the G duodenalis genotypes (synonym for assemblages). RESULTS: The most commonly occurring single assemblage was assemblage F (68.3%; n = 28/41), followed by assemblage A (12.2%; n = 5/41) and assemblage C (2.4%; n = 1/41). The mixed assemblages were identified as follows: assemblages F and A (9.8%; n = 4/41), assemblages F and C (4.9%; n = 2/41) and assemblages C and D (2.4%; n = 1/41). Additional sub-genotyping of assemblage A isolates based on three of the sequenced loci (gdh, bg and tpi ) revealed that all eight isolates were identified as sub-assemblage AI and/or AII. CONCLUSIONS AND RELEVANCE: The present study is the first to report the detection of dog-adapted assemblages C and D in feline isolates from Japan. In addition, zoonotic sub-assemblage AI and human-adapted sub-assemblage AII were also identified. Thus, we concluded that the risk of transmission of G duodenalis from breeding cattery cats to humans is considerable and cannot be ignored.

The Aldosterone Receptor Antagonist Eplerenone Inhibits Isoproterenol-Induced Collagen-I and 11ß-HSD1 Expression in Rat Cardiac Fibroblasts and the Left Ventricle.

ß-Adrenergic receptor (ß-AR)-induction of collagen-I synthesis is partially mediated by the cardiac mineralocorticoid receptor (MR) system. However, it remains unclear whether the selective MR antagonist, eplerenone, inhibits collagen-I synthesis induced by ß-AR stimulation. We investigated the effects of eplerenone on the responses to a non-selective ß-AR agonist, isoproterenol, which induced collagen-I synthesis in primary cardiac fibroblasts (CFs) and the left ventricle. mRNAs encoding the MR and 11ß-hydroxysteroid dehydrogenase type I (11ß-HSD1) were evident in the left ventricle and primary CFs. mRNAs encoding the CYP family 11 subfamily B member 2 (CYP11-B2) were not detected, even after isoproterenol treatment. In vivo, isoproterenol induced collagenous fiber accumulation in the left ventricle. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), 11ß-HSD1 levels, and mRNA/protein levels of collagen-I increased upon exposure to isoproterenol, but these increases were inhibited by eplerenone co-treatment. In primary CFs, isoproterenol increased the phosphorylation of ERK1/2 and the expression levels of both 11ß-HSD1 and collagen-I; these isoproterenol-attributable effects were inhibited by co-treatment with eplerenone and PD98059, a specific inhibitor of mitogen-activated protein kinase/ERK kinase activity. The results suggest that 11ß-HSD1 but not CYP11-B2 is expressed in primary CFs. Eplerenone inhibited isoproterenol-induced ERK1/2 phosphorylation and expression of 11ß-HSD1 and collagen-I in primary CFs, as well as the progression of cardiac fibrosis in the left ventricle. Therefore, eplerenone inhibited the isoproterenol-induced increases in 11ß-HSD1 and collagen-I expression in primary CFs, and progression of cardiac fibrosis in the left ventricle.

Molecular prevalence of Cryptosporidium species among household cats and pet shop kittens in Japan.

OBJECTIVES: To address the lack of up-to-date published data, the present study evaluates the PCR-based prevalence of Cryptosporidium species infection and molecular characteristics of isolates among household cats and pet shop kittens in Japan. METHODS: A total of 357 and 329 fresh faecal samples were collected from household cats and pet shop kittens, respectively, with or without clinical signs of infection. A nested PCR assay targeting the 18S rRNA gene was employed for the detection of Cryptosporidium species. After specific DNA fragments (approximately 826 base pairs) were confirmed, the amplicons were sequenced to determine species. RESULTS: Seven (2.0%) household cats and one (0.3%) pet shop kitten tested positive for the presence of Cryptosporidium species. In household cats, there was a significant difference in prevalence between cats aged <1 year (4.6%) and those aged ⩾1 year (0.4%). No significantly different prevalence was observed with regard to faecal condition in either household cats or pet shop kittens. A total of eight Cryptosporidium species isolates, seven from household cats and one from a pet shop kitten, were identified as Cryptosporidium felis. CONCLUSIONS AND RELEVANCE: The present study demonstrates the risk of zoonotic transmission of Cryptosporidium species from household cats and pet shop kittens to humans is low in Japan.

Influence of storage conditions on in vitro stability of atrial natriuretic peptide and of anesthesia on plasma atrial natriuretic peptide concentration in cats.

OBJECTIVE To investigate the in vitro stability of atrial natriuretic peptide (ANP) in plasma samples under various storage conditions and the influence of anesthesia on plasma ANP concentration in cats. ANIMALS 1 cat with congestive heart failure and 5 healthy adult mixed-breed cats. PROCEDURES A plasma sample from the cat with heart failure was serially diluted, and dilutional parallelism of ANP concentration was evaluated. Plasma samples containing aprotinin or serum samples from the 5 healthy cats were kept at room temperature (27°C) for ≤ 12 hours. Plasma samples from the same healthy cats were stored at -70°, -20°, or 4°C for ≤ 14 days. Plasma samples were obtained from the healthy cats before and during isoflurane anesthesia. Plasma ANP concentrations were measured at a commercial laboratory by use of a human ANP chemiluminescence assay. RESULTS Intra- and interassay coefficients of variation were 1.5% and 2.5%, respectively, and dilutional parallelism was established. Although ANP concentration decreased by 82.4 ± 13.6% (mean ± SD) after sample storage for 12 hours at room temperature, this decrease was prevented by aprotinin. Plasma ANP concentrations were stable for 7 days at -20°C and for 14 days at -70°C. However, concentrations decreased markedly to 57.6 ± 6.9% at -20°C and to 18.0 ± 3.0% at 4°C after 14 days. Plasma ANP concentration decreased significantly in cats during anesthesia and was correlated with blood pressure. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that aprotinin should be added routinely in preparation of plasma samples from cats for measurement of ANP concentration, and those samples, if stored, should be frozen immediately at ≤ -20°C. General anesthesia or systemic blood pressure may affect plasma ANP concentration in cats.

Relative potency of tyrosol in the treatment of endotoxin-induced uveitis in rats.

Tyrosol (Tyr) is a natural phenolic antioxidant with diverse biological activities. We compared the anti-inflammatory effects of intravenously administered Tyr versus prednisolone (PSL) in an endotoxin-induced uveitis (EIU) rat model. Intravenous administration of 100 mg/kg Tyr was performed 2 hr before, simultaneously and 2 hr after lipopolysaccharide (LPS) injection. Tyr treatment was associated with decreased inflammatory cell number, protein concentration, tumor necrosis factor (TNF)-α, PGE2 and NO levels in AqH and improvements in histopathologic evidence of EIU in ocular tissue at 24 hr after LPS injection. 100 mg/kg Tyr and 1 mg/kg PSL (administered on the same schedule as Tyr) had comparable anti-inflammatory effects. Taken together, Tyr may represent a promising therapeutic agent for the management of intraocular inflammatory diseases.

Therapeutic anti-inflammatory effects of luteolin on endotoxin-induced uveitis in Lewis rats.

The present study aimed to investigate the therapeutic efficacy of post-inflammatory treatment with luteolin on endotoxin-induced uveitis (EIU) in rats. Intraperitoneal injection of 10 mg/kg luteolin or 1 mg/kg prednisolone (Pred) at 4 hr post-lipopolysaccharide (LPS) injection (200 µg) was associated at 24 hr post-LPS injection with decreased clinical severity scores, number of inflammatory cells, protein levels and levels of tumor necrosis factor (TNF)-α, nitric oxide (NO) and prostaglandin (PG) E2 in the aqueous humor (AqH) and degrees of histological ocular tissue injury. The anti-inflammatory potency of luteolin was comparable to that of Pred. Luteolin exhibited robust efficacy in the treatment of EIU in rats, indicating its potential clinical utility in treating uveitis.

Tyrosol ameliorates lipopolysaccharide-induced ocular inflammation in rats via inhibition of nuclear factor (NF)-κB activation.

We evaluated the anti-inflammatory effect of tyrosol (Tyr) on endotoxin-induced uveitis (EIU) in rats. EIU was induced in male Lewis rats by subcutaneous injection of lipopolysaccharide (LPS). Tyr (10, 50 or 100 mg/kg) was intravenously injected 2 hr before, simultaneously and 2 hr after LPS injection. The aqueous humor (AqH) was collected 24 hr after LPS injection; the infiltrating cell number, protein concentration, and tumor necrosis factor (TNF)-α, prostaglandin (PG)-E2 and nitric oxide (NO) levels were determined. Histopathologic examination and immunohistochemical studies for nuclear factor (NF)-κB, inhibitor of κB (IκB)-α, cyclooxygenase (COX)-2 and inducible NO synthase (iNOS) in the iris-ciliary body (ICB) were performed at 3 or 24 hr after LPS injection. To further clarify the anti-inflammatory effects, RAW264.7 macrophages were stimulated with LPS in the presence or absence of Tyr. Tyr reduced, in a dose-dependent manner, the infiltrating cell number, protein concentration, and TNF-α, PGE2 and NO levels in AqH and improved histopathologic scores of EIU. Tyr also inhibited LPS-induced COX-2 and iNOS expression, IκB-α degradation and nuclear translocation of activated NF-κB in ICB. Tyr significantly suppressed inflammatory mediator production in the culture medium and COX-2 and iNOS expression and activated NF-κB translocation in LPS-stimulated RAW264.7 cells. These results suggest that Tyr suppresses ocular inflammation of EIU by inhibiting NF-κB activation and subsequent proinflammatory mediator production.