Identification of pimavanserin tartrate as a potent Ca2+-calcineurin-NFAT pathway inhibitor for glioblastoma therapy.

Glioblastoma multiforme (GBM) is the most common and malignant type of primary brain tumor, and 95% of patients die within 2 years after diagnosis. In this study, aiming to overcome chemoresistance to the first-line drug temozolomide (TMZ), we carried out research to discover a novel alternative drug targeting the oncogenic NFAT signaling pathway for GBM therapy. To accelerate the drug's clinical application, we took advantage of a drug repurposing strategy to identify novel NFAT signaling pathway inhibitors. After screening a set of 93 FDA-approved drugs with simple structures, we identified pimavanserin tartrate (PIM), an effective 5-HT2A receptor inverse agonist used for the treatment of Parkinson's disease-associated psychiatric symptoms, as having the most potent inhibitory activity against the NFAT signaling pathway. Further study revealed that PIM suppressed STIM1 puncta formation to inhibit store-operated calcium entry (SOCE) and subsequent NFAT activity. In cellula, PIM significantly suppressed the proliferation, migration, division, and motility of U87 glioblastoma cells, induced G1/S phase arrest and promoted apoptosis. In vivo, the growth of subcutaneous and orthotopic glioblastoma xenografts was markedly suppressed by PIM. Unbiased omics studies revealed the novel molecular mechanism of PIM's antitumor activity, which included suppression of the ATR/CDK2/E2F axis, MYC, and AuroraA/B signaling. Interestingly, the genes upregulated by PIM were largely associated with cholesterol homeostasis, which may contribute to PIM's side effects and should be given more attention. Our study identified store-operated calcium channels as novel targets of PIM and was the first to systematically highlight the therapeutic potential of pimavanserin tartrate for glioblastoma.

Ameliorative effect of acetylshikonin on cigarette smoke-induced lung inflammation in mice.

Cigarette smoke exposure is the major cause of chronic obstructive pulmonary disease (COPD). Acetylshikonin was the active principle component of Purple Gromwell that show anti-oxidative and anti-inflammatory effect. However, no data are available to elucidate the protective effect of acetylshikonin on COPD. Acetylshikonin could attenuate smoke-induced lung pathological changes, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and monocyte chemoattractant protein 1 (MCP-1) productions, and tissue damages caused by oxidative stress. Furthermore, acetylshikonin was found to enhance the expression of Nrf2 and Nur77-mediated COX-2 in vivo and in vitro.

The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases.

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular degeneration (AMD), age-related cataract (ARC), cognition diseases, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis and diabetic retinopathy. The mechanism by which they are involved in the prevention of eye diseases may be due their physical blue light filtration properties and local antioxidant activity. In addition to their protective roles against light-induced oxidative damage, there are increasing evidences that L and Z may also improve normal ocular function by enhancing contrast sensitivity and by reducing glare disability. Surveys about L and Z supplementation have indicated that moderate intakes of L and Z are associated with decreased AMD risk and less visual impairment. Furthermore, this review discusses the appropriate consumption quantities, the consumption safety of L, side effects and future research directions.

Direct observation of localized surface plasmon field enhancement by Kelvin probe force microscopy.

A surface plasmon (SP) is a fundamental excitation state that exists in metal nanostructures. Over the past several years, the performance of optoelectronic devices has been improved greatly via the SP enhancement effect. In our previous work, the responsivity of GaN ultraviolet detectors was increased by over 30 times when using Ag nanoparticles. However, the physics of the SP enhancement effect has not been established definitely because of the lack of experimental evidence. To reveal the physical origin of this enhancement, Kelvin probe force microscopy (KPFM) was used to observe the SP-induced surface potential reduction in the vicinity of Ag nanoparticles on a GaN epilayer. Under ultraviolet illumination, the localized field enhancement induced by the SP forces the photogenerated electrons to drift close to the Ag nanoparticles, leading to a reduction of the surface potential around the Ag nanoparticles on the GaN epilayer. For an isolated Ag nanoparticle with a diameter of ~200 nm, the distribution of the SP localized field is located within 60 nm of the boundary of the Ag nanoparticle. For a dimer of Ag nanoparticles, the localized field enhancement between the nanoparticles was the strongest. The results presented here provide direct experimental proof of the localized field enhancement. These results not only explain the high performance of GaN detectors observed with the use of Ag nanoparticles but also reveal the physical mechanism of SP enhancement in optoelectronic devices, which will help us further understand and improve the performance of SP-based optoelectronic devices in the future.

[Comparative Analysis of Content of Four Alkaloids in Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea].

OBJECTIVE: To establish an assay method for simultaneous determination of peimine, peiminine, peimissine and hupehenine and to make a comparative analysis of the content of four alkaloids in Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea for the first time. METHODS: A Unitary C18 column(250 mm x 4.6 mm, 5 µm) was chosen with acetonitrile-water (containing 0.05% diethylamine) as mobile phase in a gradient program. The column temperature was 35 degrees C and the flow-rate was 1.0 mL/min. RESULTS: There was high content of peiminine and the content of peimissine was inferior to peiminine in Fritillaria hupehensis. Relatively speaking, peimine and hupehenine were much lower than the other two ingredients. Fritillaria ebeiensis var. purpurea also contained high levels of peiminine, the minimum content of peimine and equivalent content of peimissine comparing with Fritillaria hupehensis. In addition, it didn't contain hupehenine in Fritillaria ebeiensis var. purpurea. CONCLUSION: This method is simple and fast, and it has good separation, reproducibility and reliable results. Also, it can be used as basis for the quality evaluation of Fritillaria hupehensis and Fritillaria ebeiensis var. purpurea.

Relationship between ambient fine particles and ventricular repolarization changes and heart rate variability of elderly people with heart disease in Beijing, China.

OBJECTIVE: To explore the effects of particulate matters less than 2.5 µm in aerodynamic diameter (PM2.5) on heart repolarization/depolarization and heart rate variability (HRV). METHODS: We conducted a panel study for elderly subjects with heart disease in Beijing from 2007 to 2008. PM2.5 was measured at a fixed station for 20 h continuously each day while electrocardiogram (ECG) indexes of 42 subjects were also recorded repeatedly. Meteorological data was obtained from the China Meteorological Data Sharing Service System. A mixed linear regression model was used to estimate the associations between PM2.5 and the ECG indexes. The model was adjusted for age, body mass index, sex, day of the week and meteorology. RESULTS: Significant adverse effects of PM2.5 on ECG indexes reflecting HRV were observed statistically and the strongest effect of PM2.5 on HRV was on lag 1 day in our study. However, there were no associations between PM2.5 and ECG indexes reflecting heart repolarization/depolarization. Additionally, the effects of PM2.5 on subjects with hypertension were larger than on the subjects without hypertension. CONCLUSION: This study showed ambient PM2.5 could affect cardiac autonomic function of the elderly people with heart disease, and subjects with hypertension appeared to be more susceptive to the autonomic dysfunction induced by PM2.5.

A Lysin motif (LysM)-containing protein functions in antibacterial responses of red swamp crayfish, Procambarus clarkii.

Lysin domain (LysM) is a widely spread domain in nature and could bind different peptidoglycans and chitin-like compounds in bacteria and eukaryotes. In plants, Lysin motif containing proteins are one of the major classes of pattern recognition proteins which can recognize GlcNAc-containing glycans and have important functions in plant immunity. However, their functions in animal immunity are still unclear. In this study, a cDNA encoding a LysM containing protein was identified from red swamp crayfish, Procambarus clarkii. The cDNA of PcLysM contained 1200 base pair nucleotides with an open reading frame of 702bp encoding a protein of 233 amino acid residues. The deduced protein had a calculated molecular mass of 25.950kDa and a pI of 6.84. Tissue distribution analysis in mRNA level showed that it was highly expressed in gills, hemocytes, and intestine, and lowly expressed in hearts, hepatopancreas, and stomach. Time course expression pattern analysis showed that PcLysM was upregulated in hemocytes and gills after challenge with Vibrio anguillarum, and it was upregulated at 12h after challenge with Staphylococcus aureus in gills. The recombinant PcLysM could bind to different bacteria, and yeast. Further study revealed that PcLysM could bind to peptidoglycans from different bacteria, and chitin. After PcLysM was knocked down, the upregulation of antimicrobial peptide (AMP) genes (crustins and antilipopolysaccharide factors) was suppressed in response to bacterial infection in gills. These results suggest that PcLysM recognizes different microorganisms through binding to polysaccharides, such as peptidoglycans and chitin and regulates the expression of some antimicrobial peptide genes though unknown pathways and regulates the expression of some antimicrobial peptide genes though unknown pathways. This study might provide a clue to elucidate the roles of PcLysM in the innate immune reaction of crayfish P. clarkii.

[Detection and significance of gene variation in hepatitis B virus S region].

OBJECTIVE: To explore the variations of gene S in hepatitis B viruses of hepatitis B patients and provide experimental evidences for the mutation analysis of viral gene. METHODS: The virus DNA load in hepatitis B patient donors was detected by real-time polymerase chain reaction (PCR) and gene sequence analysis. And a comparison was made with standard strain by the software DNAstar. RESULTS: (1) Gene S was successfully amplified and sequenced in 15 hepatitis B patients. Three samples had I→T mutation at residue 126 in HBsAg "a" antigenic determinant. (2) Sixteen hepatitis B patients had 67 nucleotide mutations, including 14 residues in PreS1 and 6 residues in PreS2. Mutations nt 3036 T→C, nt 3039 T→G, nt 3066 C→T and L88V existed in PreS1 gene in all samples. CONCLUSION: HBV genome is susceptible to nucleotide mutations. Some residues have geographically restricted mutations in gene S region. And understanding the significance of these mutations may help clarify the pathogenesis of hepatitis B and provide new experimental evidence for its gene diagnosis and prevention.

Cloning and characterization of Rap GTPase from the Chinese white shrimp Fenneropenaeus chinensis.

Ras-related protein Rap GTPase has been implicated in cell adhesion, cell proliferation, and cell junction formation. The first shrimp Rap cDNA (FcRap) was recently identified from the Chinese white shrimp Fenneropenaeus chinensis. The full length of FcRap is 1013 bp, with a 561 bp open reading frame that encodes a 186 amino acid protein. FcRap has a calculated molecular mass of 20.90 kDa and pI of 6.37. Phylogenetic analysis shows that FcRap and other Rap proteins are clustered into one group. Results from the quantitative real-time polymerase chain reaction show that FcRap could be detected mainly in the hemocytes, hepatopancreas, stomach, and gills, whereas a relatively lower expression level could be detected in the heart and intestines. FcRap in the hemocytes was upregulated 2h post Vibrio challenge, and it was upregulated 2h post white spot syndrome virus (WSSV) challenge, and peaked at 6h before it declined at 12h. No variation in the FcRap transcript was observed in the gills under the Vibrio challenge, but it was initially downregulated 2h post WSSV challenge, and then it was upregulated and peaked at 6h before it was eventually went down at 12h. The rFcRap protein was successfully expressed in Escherichia coli BL21DE3. The pull-down analysis showed that rFcRap protein could interact with VP28, an envelope protein of WSSV. The probable roles of Rap GTPase in shrimp innate immunity are presented for the first time.

[Time-series analysis on the association between gaseous air pollutants and daily mortality in urban residents in Tianjin].

OBJECTIVE: To study the association between sulphur dioxide, nitrogen dioxide and daily mortality in urban population from Tianjin. METHODS: Data on daily concentration of inhalable particulate matter, sulphur dioxide and nitrogen dioxide, daily mean temperature and relative humidity, daily cause-specific death counts were collected. Generalized additive models was used to explore the relationship between sulphur dioxide, nitrogen dioxide and daily mortality, after adjusting the effects of long-term and seasonal trend, weather conditions, and to analyze the potential effect of particulate matter and model parameters on relative risk estimates. RESULTS: Results showed that the daily concentrations of SO(2) and NO(2) were significantly associated with daily non-accidental and cardiovascular mortality but not associated with daily respiratory mortality. An increase of 10 µg/m(3) in SO(2) was associated with 0.56% (95%CI: 0.23% - 0.89%) non-accidental morality, 0.49% (0.06% - 0.93%) cardiovascular morality, respectively. An increase of 10 µg/m(3) in NO(2) was associated with 0.94% (95%CI: 0.17% - 1.70%) non-accidental morality, 1.29% (0.29% - 2.30%) cardiovascular morality, respectively. CONCLUSION: Our findings suggested that exposure to SO(2) and NO(2) was significantly associated with daily cardiovascular and respiratory mortality in urban population in Tianjin.

[Time-series analysis of association between inhalable particulate matter and daily mortality among urban residents in Tianjin].

OBJECTIVE: To study the association between particulate matter less than 10 micron in aerodynamic diameter (PM(10)) and daily mortality among urban population in Tianjin. METHODS: We collected data of air quality, daily mean temperature and relative humidity, and daily cause-specific death counts, and used generalized additive models to explore the relationship between ambient particulate matter and daily mortality, after adjusting the effects of long-term and seasonal trend, weather conditions and other gaseous pollutants, such as sulfur dioxide and nitrogen dioxide. RESULTS: An increase of 10 µg/m(3) in PM(10) was associated with 0.45% (95%CI: 0.21 - 0.69) non-accidental morality, 0.60% (0.29 - 0.91) circulatory morality and 0.82% (0.04 - 1.61) respiratory morality, respectively. CONCLUSION: Our findings indicated that the extent of exposure to PM(10) was significantly associated with daily mortality in urban population in Tianjin, especially with the mortality rates on circulatory and respiratory diseases.

Polymorphisms of Epstein-Barr virus BHRF1 gene, a homologue of bcl-2.

BACKGROUND AND OBJECTIVE: EBV BamHI fragment H rightward open reading frame 1 (BHRF1), the Epstein-Barr virus (EBV) early gene, is structurally and functionally homologous to the oncogene bcl-2 and may play an important role in the development of EBV-associated tumors. To characterize the polymorphisms of BHRF1 in EBV-associated tumors, we analyzed the sequences of BHRF1 in isolates from nasopharyngeal carcinoma (NPC) and EBV-associated gastric carcinoma (EBVaGC) biopsies as well as throat washing (TW) samples from healthy donors. METHODS: BHRF1 DNA sequences were analyzed by polymerase chain reaction (PCR) and sequencing for 39 NPC samples, 40 EBVaGC samples, and 53 EBV-positive TW samples from healthy donors. The variants of BHRF1 gene were classified according to the signature changes. The EBV types 1 and 2 at nuclear antigen (EBNA) 3C locus were determined by PCR. RESULTS: Compared with EBV standard cell line B95-8, all isolates carried a silent mutation at amino acid (AA) 80 (nucleotide 54616 T→C), the AA88 L→V mutation was found in most isolates, and the AA79 V→L mutation in a few isolates. Other mutations were sporadically distributed. Based on the mutations at AA88 and AA79, 3 distinct variants of BHRF1 genes, designated as 79V88V, 79L88L, and 79V88L, were identified. The 79V88V was the most common variant. The distribution of the BHRF1 variants among the NPC, EBVaGC, and TW samples was not significant. The corresponding regions of bcl-2 homologues were conserved in all isolates except for 3 samples. The distribution of BHRF1 variants in type 1 and type 2 strains was significant different (P < 0.001, contingency coefficient was 0.554). CONCLUSIONS: The 79V88V is the dominant variant in NPC, EBVaGC, and TW samples from healthy donors and preferential linkages between BHRF1 and EBNA3C variants exist. Conserved BHRF1 in Bcl-2 homologous domains is helpful to remain the important role of BHRF1.

T-type calcium channel blockers: spiro-piperidine azetidines and azetidinones-optimization, design and synthesis.

A series of spiro-azetidines and azetidinones has been evaluated as novel blockers of the T-type calcium channel (Ca(V)3.2) which is a new therapeutic target for the potential treatment of both inflammatory and neuropathic pain. Confirmation and optimization of the potency, selectivity and DMPK properties of leads will be described.

[The correlations between air quality and heart rate variability in aged susceptible people during Beijing Olympic Games 2008].

OBJECTIVE: To observe the variations of the concentrations of air pollutants and explore the correlation between the heart rate variability (HRV) of the aged people and the air quality during Beijing Olympic Games 2008. METHODS: A panel study design was adopted. A total of twenty-six over 55-year-old patients with coronary heart disease or angina pectoris or a symptom of myocardial ischemia at least for one year were enrolled as a panel and followed up five times by measuring HRV index and other related indexes from June to September in 2008. The correlations between the HRV of the aged people and the air quality was analyzed with the linear mixed-effect models according to the data of air pollutants and meteorological conditions collected simultaneously from Beijing Environmental Protection Bureau and Beijing Meteorological Bureau. RESULTS: In single-pollutant mixed-effect models, the significant correlation was observed in the reduction of ambient PM(10), SO(2) and NO(2) with the improvement of the total power and high-frequency power (HF) of HRV in the panel subjects, and a 10 microg/m(3) decrease in PM(10), SO(2) and NO(2) level was correlated with 2.51% (95%CI: -3.80% - -1.22%, t = -1.99, P = 0.0497), 31.39% (95%CI: -52.24% - -10.53%, t = -1.99, P = 0.0497) and 42.72% (95%CI: -75.06% - -10.38%, t = -1.99, P = 0.0497) rises in total power of HRV respectively. A 10 microg/m(3) decrease in PM(10), SO(2) and NO(2) level was correlated with 3.46% (95%CI: -5.14% - -1.77%, t = -2.11, P = 0.0378), 40.63% (95%CI: -68.70% - -12.56%, t = -2.11, P = 0.0378) and 53.76% (95%CI: -97.97% - -9.56%, t = -2.11, P = 0.0378) rises in high-frequency power (HF) of HRV respectively. CONCLUSION: It suggests that the air pollution reduction could improve the cardiovascular functions of the susceptible population.

Identification and molecular characterization of a Spätzle-like protein from Chinese shrimp (Fenneropenaeus chinensis).

In invertebrates, the Toll signaling pathway is important for activation of antimicrobial peptides in the innate immune system. Activation of the Toll pathway requires binding of Toll with its ligand Spätzle. Here we described a Spätzle-like protein, designated as Fc-Spz, from hemocytes of Chinese shrimp, Fenneropenaeus chinensis. The deduced amino acid sequence of Fc-Spz shares 54% identity with Spätzle-like protein of salmon louse (Lepeophtheirus salmonis). Semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), quantitative real time PCR, and Western blot analyses were carried out to analyze the expression pattern and distribution profile of Fc-Spz in shrimp after challenged with bacteria and virus. The results showed that Fc-Spz mRNA was up-regulated in all the tissues tested in shrimp injected with Vibrio anguillarum and white spot syndrome virus (WSSV). The C-terminal active Fc-Spz domain (114 residues) was expressed in Escherichia coli and purified by affinity chromatography. The recombinant Fc-Spz C-114 was injected into crayfish (Procambarus clarkii) to determine the expression levels of several antimicrobial peptide genes. The results showed that recombinant Fc-Spz C-114 could up-regulate crustin 2 expression in crayfish. These results suggest that Fc-Spz may play a role in the innate immune defence of Chinese shrimp and crayfish.

A hepatopancreas-specific C-type lectin from the Chinese shrimp Fenneropenaeus chinensis exhibits antimicrobial activity.

Lectins play important roles in animal innate immune responses by serving as pattern recognition receptors, opsonins, or effector molecules. Here, we report a novel hepatopancreas-specific C-type lectin, designated Fc-hsL, from the hepatopancreas of the Chinese shrimp, Fenneropenaeus chinensis. The cDNA of Fc-hsL is 571 bp long with a 480 bp open reading frame that encodes a 159-residue protein. Fc-hsL contains a signal peptide and a single C-type lectin-like domain (CTLD) or carbohydrate recognition domain (CRD). It has an EPN(Glu-Pro-Asn) motif with a predicted ligand-binding site specific for mannose. Fc-hsL was constitutively expressed in the hepatopancreas of normal shrimp, and its expression was up-regulated following challenge of shrimp with bacteria or virus. Fc-hsL was not detected in other tissues but was induced in the stomach of immune-challenged shrimp. Fc-hsL protein was detected in both hemolymph and the hepatopancreas of bacteria- and virus-challenged shrimp. Recombinant mature Fc-hsL has no hemagglutinating activity, but calcium-dependent agglutinating activity against some Gram-positive and Gram-negative bacteria was detected. The rFc-hsL also has binding activity to some Gram-positive and Gram-negative bacteria and high antimicrobial activity against some bacteria and fungi. These in vitro functions of recombinant Fc-hsL were calcium-independent. Fc-hsL may act as a pattern recognition receptor in antibacterial defense and as an effector in innate immunity of Chinese shrimp.

Safety and immunogenicity from a phase I trial of inactivated severe acute respiratory syndrome coronavirus vaccine.

BACKGROUND: Emergence of severe acute respiratory syndrome (SARS) from the winter of 2002 to the spring of 2003 has caused a serious threat to public health. METHODS: To evaluate the safety and immunogenicity of the inactivated SARS coronavirus (SARS-CoV) vaccine, 36 subjects received two doses of 16 SARS-CoV units (SU) or 32 SU inactivated SARS-CoV vaccine, or placebo control. RESULTS: On day 42, the seroconversion reached 100% for both vaccine groups. On day 56, 100% of participants in the group receiving 16 SU and 91.1% in the group receiving 32 SU had seroconverted. The geometric mean titre of neutralizing antibody peaked 2 weeks after the second vaccination, but decreased 4 weeks later. CONCLUSION: The inactivated vaccine was safe and well tolerated and can elicit SARS-CoV-specific neutralizing antibodies.

Cyclo-oxygenase-2 contributes to central sensitization in rats with peripheral inflammation.

It has been widely accepted that prostaglandins are involved in peripheral mechanisms of hyperalgesia. Several lines of evidence suggest that prostaglandins also contribute to the mechanisms underlying hyperalgesia at the level of the spinal cord. The nociceptive flexor reflex of the hind limb was used to test the hypothesis that products of cyclo-oxygenase contribute to the increased excitability of spinal neurons during hyperalgesia induced by peripheral injection of complete Freund's adjuvant (CFA) into the hind paw. The reflex was evoked by electrical stimulation of the sural nerve at an intensity that activated A- and C-fibers, and muscle potentials were recorded in hamstring muscles in decerebrate, spinalized rats. Intrathecal administration of (S)-ibuprofen (1-100 nmol) dose-dependently attenuated the flexor reflex in CFA treated rats but had no effect in untreated rats. (R)-Ibuprofen had no effect on the reflex in either control or CFA-treated rats at the dose tested (100 nmol). Western blots of lumbar spinal cord extracts showed increased levels of cyclo-oxygenase (COX)-2 protein in the dorsal spinal cord of rats with peripheral inflammation; no change occurred in the level of COX-1. These results indicate that products of COX-2 contribute to the increased excitability of the spinal cord during persistent peripheral inflammation.

Activation of spinal ORL-1 receptors prevents acute cutaneous neurogenic inflammation: role of nociceptin-induced suppression of primary afferent depolarization.

Neurogenic inflammation is an inflammatory response of peripheral tissue to vasoactive substances released from sensory afferent terminals. It can be triggered via a local axon reflex and by dorsal root reflex (DRR) activity involving the spinal cord. Nociceptin, an endogenous ligand for the opioid receptor-like (ORL-1) G-protein coupled receptor, has been found to inhibit the local axon reflex-mediated neurogenic inflammation by suppressing the release of vasoactive neuropeptides from sensory afferent terminals. The present study was to explore the role of spinal ORL-1 receptors in the modulation of DRR-induced neurogenic inflammation. We first examined the effect of nociceptin on DRR by recording dorsal root potentials (DRPs) and the associated antidromic discharges, evoked by electrical stimulation of an adjacent dorsal root in an in vitro neonatal rat spinal cord preparation. Nociceptin reversibly inhibited the DRP in a concentration-dependent manner (IC50: approximately 45 nM, maximal inhibition: approximately 50%), an effect that was antagonized by the ORL-1 receptor antagonist, J-113397. Neurochemical studies demonstrated that nociceptin (10 microM) also produced an approximately 40% reduction in gamma amino butyric acid (GABA) release evoked by electrical stimulation of neonatal rat spinal cord slices. On the other hand, nociceptin had no effect on exogenous GABA-evoked DRP. These findings suggest that the nociceptin-induced inhibition of the DRP is most likely due to the suppression of GABA release, the principle transmitter mediating DRP, from GABAergic neurons that are pre-synaptic to primary afferent terminals. Finally, in order to explore the physiological significance of such modulation in a fully integrated system, we evaluated the effect of intrathecally administered nociceptin on capsaicin-induced acute cutaneous neurogenic inflammation in rat hind paw, quantified by examining the degree of paw edema in anesthetized rats. The magnitude of capsaicin-induced increase of paw thickness was reduced by approximately 50% from 31+/-1.34% (n=6) to 15+/-1.63% (n=8; P<0.05) by nociceptin (10 micromol). We conclude that spinal ORL-1 receptors can modulate neurogenic inflammation by suppressing the GABAergic neuronal activity in the dorsal horn that is responsible for generating DRRs.