Effect of intratracheal instillation of ultrafine carbon black on proinflammatory cytokine and chemokine release and mRNA expression in lung and lymph nodes of mice

Our understanding of how ultrafine particles, which are constituents of particulate matter, affect immunological response is poor. To investigate the size-specific effect of ultrafine particles on pulmonary immune responses, translocation to lymph nodes, and chemokine mRNA expressions in lung and lymph nodes, we performed three experiments in 8-week-old male BALB/c mice. In experiment 1, we instilled 25 microg, 125 microg, or 625 microg of 14 nm carbon black (CB) particles intratracheally, once weekly for 4 weeks, and in experiment 2, we instilled 95 nm CB. For detection of total and differential cell counts and cytokine and chemokine protein release, we collected bronchoalveolar lavage (BAL) fluid 24 h after the last instillation of CB. Experiments 1 and 2 showed that 125 microg was the suitable dose for experiment 3, which we then performed on the same schedule and 4 h after the last instillation, we harvested the lung and mediastinal lymph node to detect chemokine mRNA expression by real-time RT-PCR. The total cell count as well as the differential cell counts such as macrophages, lymphocytes, and neutrophils in BAL fluid increased significantly in mice exposed to 14 nm CB in a dose-dependent manner. Release of cytokines such as interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha increased significantly in BAL fluid in mice instilled with 14-nm CB. Macrophage inflammatory protein 1 alpha/CCL-3 protein and mRNA expression were increased significantly in the lungs and lymph nodes of mice given 14 nm CB. Histologically, deposition of CB was observed greater in the mediastinal lymph nodes of mice given 14 nm than in 95 nm CB. These findings indicate that repeated intratracheal instillation of ultrafine carbon black in mice leads to pulmonary inflammation, their translocation to mediastinal lymph nodes and increased chemokine mRNA expression in lung and lymph nodes size-specifically.     

Ultrafine carbon black particles cause early airway inflammation and have adjuvant activity in a mouse allergic airway disease model.

To gain more insight into the mechanisms of particulate matter (PM)-induced adjuvant activity, we studied the kinetics of airway toxicity/inflammation and allergic sensitization to ovalbumin (OVA) in response to ultrafine carbon black particles (CBP). Mice were exposed intranasally to OVA alone or in combination with different concentrations of CBP. Airway toxicity and inflammation were assessed at days 4 and 8. Immune adjuvant effects were studied in the lung draining peribronchial lymph nodes (PBLN) at day 8. Antigen-specific IgE was measured at days 21 and 28, whereas allergic airway inflammation was studied after OVA challenges (day 28). Results show that a total dose of 200 microg CBP per mouse, but not 20 microg or 2 microg, induced immediate airway inflammation. This 200 microg CBP was the only dose that had immune adjuvant activity, by inducing enlargement of the PBLN and increasing OVA-specific production of Th2 cytokines (IL-4, IL-5, and IL-10). The immune adjuvant activity of 200 microg CBP dosing was further examined. Whereas increased OVA-specific IgE levels in serum on day 21 confirms systemic sensitization, this was further supported by allergic airway inflammation after challenges with OVA. Our data show a link between early airway toxicity and adjuvant effects of CBP. In addition, results indicate that local cytokine production early after exposure to CBP is predictive of allergic airway inflammation. In addition this model appears suitable for studying the role of airway toxicity, inflammation and other mechanisms of particle adjuvant activity, and predicting the adjuvant potential of different particles.     

Effect of preexposure to ultrafine carbon black on respiratory syncytial virus infection in mice.

Epidemiological studies have indicated that exposure to elevated levels of particulate matter exacerbates several pulmonary diseases, including asthma, bronchitis, and viral infections. Respiratory syncytial virus (RSV) is the major cause of bronchiolitis and pneumonia in infants and may lead to the development of asthma in childhood. To determine whether particle exposure modulates the immune response to RSV, eight-week-old female BALB/c mice received an intratracheal (i.t.) instillation of either 40 micro g ultrafine carbon black (CB) particles or vehicle. The following day, mice were i.t. instilled with either 106 pfu RSV or uninfected media. End points were examined 1, 2, 4, 7, and 10 days during RSV infection. Compared with RSV alone, tumor necrosis factor-alpha (TNF-alpha) protein was reduced in the bronchoalveolar lavage fluid (BALF) on days 1 and 2 of infection; there was also a reduction in BALF lymphocyte numbers on day 4, which correlated with reductions in both IFN-gamma-inducible protein (IP-10), lymphotactin, and IFN-gamma mRNAs in the lungs of RSV + CB mice. Multiprobe ribonuclease protection assays of RSV + CB lung tissue showed no changes in the RSV-associated chemokines regulated upon activation, normal T cell expressed and secreted (RANTES), eotaxin, monocyte chemoattractant protein (MCP-1), macrophage inflammatory protein (MIP)-1 alpha or MIP-1 beta. Viral titers in RSV + CB mice were lower than RSV on days 2-4 of infection. By day 7 of infection, however, neutrophil numbers, proinflammatory cytokine mRNA expression, and protein levels of TNF-alpha and the Th2 cytokine interleukin (IL)-13 were increased in the lungs of RSV + CB mice, indicating an exacerbation of infection. These data indicate that preexposure to ultrafine particles induces an inflammatory milieu promoting allergic immune responses rather than IFNgamma production necessary for microbial defense.     

Influence of experimental type 1 diabetes on the pulmonary effects of diesel exhaust particles in mice

Epidemiologically, exposure to particulate air pollution is associated with increases in morbidity and mortality, and diabetics are especially vulnerable to effects of particles. This study was carried out to determine the respiratory effect of diesel exhaust particles (DEP; 0.4 mg/kg) on mice rendered diabetic by the injection of streptozotocin or vehicle (control). Four weeks following induction of diabetes, the animals were intratracheally instilled (i.t.) with DEP (0.4 mg/kg) or saline. 24 h later, the measurement of airway reactivity to methacholine in vivo by a forced oscillation technique showed a significant and dose-dependent increase in airway resistance in non-diabetic mice exposed to DEP versus non-diabetic mice exposed to saline. Similarly, the airway resistance was significantly increased in diabetic mice exposed to DEP versus diabetic mice exposed to saline. Nevertheless, there was no difference in the airway resistance between diabetic and non-diabetic mice after i.t. administration of DEP. Following DEP administration there were neutrophil polymorphs infiltration of pulmonary interalveolar septae and the alveolar spaces with many macrophages containing DEP in both diabetic and non-diabetic mice. Interestingly, apoptotic cells were only found in the examined lung sections from diabetic mice exposed to DEP. Total proteins and albumin concentrations in bronchoalveolar lavage (BAL) fluid, markers for increase of epithelial permeability, were significantly increased in diabetic mice exposed to DEP compared to saline-treated diabetic and DEP-treated non diabetic mice. Superoxide dismutase activity and reduced glutathione concentration in BAL were significantly decreased in diabetic mice exposed to DEP compared to saline-treated diabetic and DEP-treated non diabetic mice. Moreover, tumor necrosis factor α (TNFα) concentrations were significantly increased in diabetic mice exposed to DEP compared to saline-treated diabetic and DEP-treated non diabetic mice. We conclude that, at the dose and time point investigated, DEP equally increased airway resistance and caused infiltration of inflammatory cells in the lung of both diabetic and non-diabetic mice. However, the occurrence of oxidative stress, the presence lung apoptotic cells and the increase of total proteins, albumin and TNFα in BAL fluid were only seen in DEP-exposed diabetic mice suggesting an increased respiratory susceptibility to particulate air pollution.     

Effect of polystyrene particles on lung microvascular permeability in isolated perfused rabbit lungs: role of size and surface properties

The aim of this study was to investigate the role of particle number, total surface area, mass and surface chemical groups in (K(f,c)) changes. The lung effects of four different fine (110 nm) and ultrafine (24 nm) polystyrene particles have been tested in an isolated perfused rabbit lung model. Pulmonary microvascular permeability (K(f,c)) modifications were measured in response to intratracheal particle challenge. Polystyrene particles, mainly located in alveolar spaces and macrophages, induced a K(f,c) increase that was related to the total surface area and number of particles rather than to the instilled mass. Moreover, the positively charged amine-modified polystyrene particles were more effective in the K(f,c) response than the negatively charged carboxylate-modified polystyrene particles. We concluded that particle number and diameter that mathematically equally determined total surface area do not have the same importance in explaining the biological effects observed and that particle number could be an alternative to total surface area to describe the particle exposure. Furthermore, surface properties of polystyrene particles need to be considered to investigate the microvascular permeability changes measured in our model.     

The pulmonary deposition and retention of indium-111 labeled ultrafine carbon particles in healthy individuals

Context: Particulate air pollution, for example, from ultrafine (UF) particles, has negative health effects. However, there is still limited knowledge regarding the fate of inhaled particles in the human body.

Objectives: To describe the normal lung deposition and 1 week particle retention of indium-111 labeled UF carbon particles in healthy subjects. Additionally, the possibility to extend the follow-up period to 4 weeks was also investigated for one of the subjects.

Results: The cumulative pulmonary particle clearance 1 week post-administration, corrected for activity leaching and mucocilliary transport of activity deposited in the central airways, was 4.3?±?8.5% (average ± standard deviation at group level), with marginal translocation of particles from lungs to blood, 0.3%. There was no observable elimination of particles from the body via urine. Seven days after exposure, the cumulated activity leaching was 3% (group level), which indicates a stable bonding between the particles and Indium-111. The volunteer followed for a total of 4 weeks, showed a cumulative decrease of activity retention in the lungs of 10.5%. After correction for activity leaching and clearance from central airway deposition, the estimated particle clearance was about 2%.

Conclusions: No evidence for particle translocation from the lungs could be proven 7 days after exposure. It is possible to follow-up Indium-111 labeled UF carbon particles at least 1 month post-administration without increasing the administered activity.     

Effect of traxanox on antibody formation in BALB/c mice

The production of spleen- and thymus-rosette forming cells (RFC) in BALB/c mice 4 days after immunization with 5 X 10(8) sheep red blood cells (SRBC) was inhibited by traxanox at doses of 10-30 mg/kg, p.o. This agent (100 mg/kg, p.o.) suppressed the 19S hemagglutinin titer and elevated the 7S hemagglutinin titer. The transfer of spleen-RFC of thymus-RFC into syngeneic recipient mice 4 days after immunization with SRBC increased the production of spleen hemolytic plaque forming cells (HPFC). This increase was abolished by the transfer of spleen-RFC obtained from mice treated with traxanox (30 mg/kg, p.o.), but not by the transfer of spleen-RFC treated with anti-Lyt 2.2 antiserum and complement. The viability of the spleen-RFC in mice treated with traxanox was decreased by treatment with anti-Lyt 2.2 antiserum and complement. Traxanox (3-30 mg/kg, p.o) significantly increased the inhibition of HPFC, spleen-RFC and thymus-RFC production by Concanavalin A at a dose of 50 micrograms/mouse. This agent (3-30 mg/kg, p.o) inhibited the production of HPFC, spleen-RFC and thymus-RFC in mice 4 days after the secondary immunization. These results suggest that traxanox may inhibit antibody production via the induction of Lyt 2.2 positive cells (suppressor T cells).     

Enhancement of antigen-induced eosinophilic inflammation in the airways of mast-cell deficient mice by diesel exhaust particles

The present study was conducted to clarify the involvement of mast cells in the exacerbating effect of diesel exhaust particles (DEP) toward allergic airway inflammation and airway hyperresponsiveness (AHR). Airway inflammation by the infiltration of cosinophils with goblet cell proliferation and AHR, as well as by the production of antigen-specific IgG1 and IgE, in plasma were examined using mast cell-deficient mice (W/W^v) and normal mice (W/W⁺). Both groups of mice received ovalbumin (OVA) or OVA+DEP intratracheally. The eosinophilic airway inflammation and goblet cell proliferation promoted by OVA were significantly greater in W/W⁺ than in W/W^v. A similar result was observed in AHR, but was not significant among both groups of mice. DEP enhanced OVA induced-allergic airway inflammation, goblet cell proliferation, and development of AHR in W/W^v, but not in W/W⁺. DEP decreased production of antigen-specific IgG1 and IgE in both groups of mice. Mast cells were observed in the submucosal layer of the main bronchus in W/W^v. The number of mast cells was significantly decreased by OVA treatment. The results indicate that mast cells are not necessary to enhance airway damage and development of AHR in W/W^v by DEP. However, mast cells may be required for the OVA-induced cosinophilic inflammation, airway damage with goblet cell proliferation, and AHR in W/W⁺.     

Potential of Azadirachta indica against Salmonella typhimurium-induced inflammation in BALB/c mice

Objective:  To evaluate the potential of Azadirachta indica leaf extracts against Salmonella typhimurium-induced inflammation in BALB/c mice. Design:  Qualitative tests of A. indica leaf extracts were conducted for screening of various phytochemicals. The antiinflammatory potential of A. indica leaf extracts on S. typhimurium and its outermembrane proteins (OMPs)-induced inflammation was assessed by hyperalgesic (flicking) response of the mice inflammed paws. The monokines (IL-1α, IL-6 and TNF-α) activities in the culture supernatants of macrophages (infected with bacteria and interacted with OMPs) in the presence or absence of A. indica leaf extracts was assessed by ELISA. Results:  Aqueous and petroleum ether A. indica leaf extracts reduced the inflammation caused by S. typhimurium and its OMPs as assessed by paw flicking response. Petroleum ether A. indica leaf extract was found to be more effective than aqueous A. indica leaf extract. Significantly lower levels of monokines (IL-6 and TNF-α) were also observed in the presence of petroleum ether A. indica leaf extracts than aqueous A. indica leaf extract. These observations may be due to the presence of steroids and triterpenoids observed in petroleum ether extract. Conclusion:  Petroleum ether A. indica leaf extract seems promising to combat S. typhimurium-induced inflammation. Received 6 June 2008; accepted 29 October 2008     

Effect of submicron and nano-iron oxide particles on pulmonary immunity in mice

Due to advances in nanotechnology, exposure to particle compounds in the workplace has become unavoidable. Assessment of their toxicity on health is an important occupational safety issue. This study was conducted in mice to investigate the toxicological effects of submicron and nano-iron oxide particles on pulmonary immune defences. In that purpose, we explored for the first time, inflammatory and immune responses in lung-associated lymph nodes. For each particle type, mice received either a single intratracheal instillation at different concentrations (250, 375, or 500μg/mouse) or four repeated instillations at 500μg/mouse each. Cytokine production, inflammatory and innate immune response, and humoral immune response were respectively assessed 1, 2, and 6 days after particle exposures. Both types of particles induced lung inflammation associated with increased cytokine productions in lymph node cell cultures and decreased pulmonary immune responses against sheep erythrocytes. Natural killer activity was not modified by particles. In comparison to single instillation, repeated instillations resulted in a reduction of inflammatory cell numbers in both bronchoalveolar lavages and pulmonary parenchyma. Moreover, the single instillation model demonstrated that, for a same dose, nano-iron oxide particles produced higher levels of inflammation and immunodepression than their submicron-sized counterparts.     

Effects of Tityus serrulatus scorpion venom on lung mechanics and inflammation in mice

The present study evaluated the effects of an intramuscular injection of Tityus serrulatus venom (TsV) (0.67 μg/g) on lung mechanics and lung inflammation at 15, 30, 60 and 180 min after inoculation. TsV inoculation resulted in increased lung elastance when compared with the control group (p < 0.001); these values were significantly higher at 60 min than at 15 and 180 min (p < 0.05). Resistive pressure (ΔP₁) values decreased significantly at 30, 60 and 180 min after TsV injection (p < 0.001). TsV inoculation resulted in increased lung inflammation, characterised by an increased density of mononuclear cells at 15, 30, 60 and 180 min after TsV injection when compared with the control group (p < 0.001). TsV inoculation also resulted in an increased pulmonary density of polymorphonuclear cells at 15, 30 and 60 min following injection when compared to the control group (p < 0.001). In conclusion, T. serrulatus venom leads to acute lung injury, characterised by altered lung mechanics and increased pulmonary inflammation.     

Endocytosis, oxidative stress and IL-8 expression in human lung epithelial cells upon treatment with fine and ultrafine TiO2: role of the specific surface area and of surface methylation of the particles

Inhaled ultrafine particles show considerably stronger pulmonary inflammatory effects when tested at equal mass dose with their fine counterparts. However, the responsible mechanisms are not yet fully understood. We investigated the role of particle size and surface chemistry in initiating pro-inflammatory effects in vitro in A549 human lung epithelial cells on treatment with different model TiO(2) particles. Two samples of TiO(2), i.e. fine (40-300 nm) and ultrafine (20-80 nm) were tested in their native forms as well as upon surface methylation, as was confirmed by Fourier transformed infrared spectroscopy. Radical generation during cell treatment was determined by electron paramagnetic resonance with 5,5-dimethyl-1-pyrroline-N-oxide or 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl. Interleukin-8 mRNA expression/release was determined by RT-PCR and ELISA, whereas particle uptake was evaluated by transmission electron microscopy. TiO(2) particles were rapidly taken up by the cells, generally as membrane bound aggregates and large intracellular aggregates in vesicles, vacuoles and lamellar bodies. Aggregate size tended to be smaller for the ultrafine samples and was also smaller for methylated fine TiO(2) when compared to non-methylated fine TiO(2). No particles were observed inside nuclei or any other vital organelle. Both ultrafine TiO(2) samples but not their fine counterparts elicited significantly stronger oxidant generation and IL-8 release, despite their aggregation state and irrespective of their methylation. The present data indicate that ultrafine TiO(2), even as aggregates/agglomerates, can trigger inflammatory responses that appear to be driven by their large surface area. Furthermore, our results indicate that these effects result from oxidants generated during particle-cell interactions through a yet to be elucidated mechanism(s).     

Size effects of latex nanomaterials on lung inflammation in mice

Effects of nano-sized materials (nanomaterials) on sensitive population have not been well elucidated. This study examined the effects of pulmonary exposure to (latex) nanomaterials on lung inflammation related to lipopolysaccharide (LPS) or allergen in mice, especially in terms of their size-dependency. In protocol 1, ICR male mice were divided into 8 experimental groups that intratracheally received a single exposure to vehicle, latex nanomaterials (250 μg/animal) with three sizes (25, 50, and 100 nm), LPS (75 μg/animal), or LPS plus latex nanomaterials. In protocol 2, ICR male mice were divided into 8 experimental groups that intratracheally received repeated exposure to vehicle, latex nanomaterials (100 μg/animal), allergen (ovalbumin: OVA; 1 μg/animal), or allergen plus latex nanomaterials. In protocol 1, latex nanomaterials with all sizes exacerbated lung inflammation elicited by LPS, showing an overall trend of amplified lung expressions of proinflammatory cytokines. Furthermore, LPS plus nanomaterials, especially with size less than 50 nm, significantly elevated circulatory levels of fibrinogen, macrophage chemoattractant protein-1, and keratinocyte-derived chemoattractant, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. In protocol 2, latex nanomaterials with all sizes did not significantly enhance the pathophysiology of allergic asthma, characterized by eosinophilic lung inflammation and Igs production, although latex nanomaterials with less than 50 nm significantly induced/enhanced neutrophilic lung inflammation. These results suggest that latex nanomaterials differentially affect two types of (innate and adaptive immunity-dominant) lung inflammation.     

Effect of D-limonene on immune response in BALB/c mice with lymphoma

The monoterpene D-limonene and its metabolites have been shown to exert chemopreventive and chemotherapeutic activities against different tumors in animal models and clinical trials. However, it is unknown whether these compounds modulate the immune response in tumor-bearing mice. We evaluated the survival of lymphoma-bearing mice fed with a diet with D-limonene. To assess the cell immune response, we sensitized and challenged BALB/c mice with 2,4-dinitrofluorobenzene (DNFB) and evaluated the T-cell subpopulations by flow cytometry. We also examined phagocytosis, microbicidal activity and chemotactic function in peritoneal macrophages. In order to know the role of D-limonene and its metabolites, macrophage NO production and lymphocyte proliferation studies were performed in vitro with D-limonene, perillic acid and perillyl alcohol. The results showed that D-limonene increased the survival of lymphoma-bearing mice, delayed hypersensitivity reaction to DNFB, phagocytosis and microbicidal activity. In vitro studies indicate that D-limonene increased NO production in peritoneal macrophages obtained from tumor-bearing mice. Our data suggest that in addition to reported properties, D-limonene modulates the immune response with significant potential for clinical application.     

重组毕赤酵母HBsAg诱导小鼠细胞免疫应答的研究

目的   研究毕赤酵母表达的重组HBsAg(Pichia-rHBsAg)在小鼠中诱导T细胞免疫应答的能力,评价疫苗的免疫原性.   方法  以rHBsAg免疫雌性BALB/c小鼠,制备小鼠脾淋巴细胞,并在体外以抗原/特异性多肽刺激.采用ELISA法测定抗原特异性T淋巴细胞分泌的细胞因子,酶联免疫斑点法(ELISPOT)测定CTL频数.   结果 由毕赤酵母表达的rHBsAg可在小鼠中诱导Th1和Th2型免疫应答;加铝佐剂的rHBsAg诱导IFN-γ的水平及CTL克隆明显高于无佐剂抗原;Pichia-rHBsAg刺激小鼠细胞免疫应答的水平强于酵母-rHBsAg,与中国仓鼠卵巢细胞-rHBsAg相仿.   结论   Pichia-rHBsAg可在BALB/c小鼠中诱导较强的细胞免疫应答.     

Copaiba oil suppresses inflammation in asthmatic lungs of BALB/c mice induced with ovalbumin

Asthma is a chronic inflammatory disease that represents high hospitalizations and deaths in world. Copaiba oil (CO) is popularly used for relieving asthma symptoms and has already been shown to be effective in many inflammation models. This study aimed to investigate the immunomodulatory relationship of CO in ovalbumin (OVA)-induced allergic asthma. The composition of CO sample analyzed by GC and GC–MS and the toxicity test was performed in mice at doses of 50 or 100 mg/kg (by gavage). After, the experimental model of allergic asthma was induced with OVA and mice were orally treated with CO in two pre-established doses. The inflammatory infiltrate was evaluated in bronchoalveolar lavage fluid (BALF), while cytokines (IL-4, IL-5, IL-17, IFN-γ, TNF-α), IgE antibody and nitric oxide (NO) production was evaluated in BALF and lung homogenate (LH) of mice, together with the histology and histomorphometry of the lung tissue. CO significantly attenuated the number of inflammatory cells in BALF, suppressing NO production and reducing the response mediated by TH2 and TH17 (T helper) cells in both BALF and LH. Histopathological and histomorphometric analysis confirmed that CO significantly reduced the numbers of inflammatory infiltrate in the lung tissue, including in the parenchyma area. Our results indicate that CO has an effective in vivo antiasthmatic effect.     

Effect of atovastatin treatment on porcine circovirus 2 infection in BALB/c mice

The HMG‐CoA reductase (HMGCR) pathway is an important metabolic route, which is not only present in almost every organism, but also involves virus infection. It has recently been shown that expression levels of IFN‐responsive genes were significantly increased in HMGCR‐downregulated cells and HMGCR inhibitor‐treated cells. The aim of this study was to determine whether inhibition of HMGCR by atovastatin would significantly affect Porcine circovirus type 2 (PCV2) infection and immunological reaction in BALB/c mice. The results showed atovastatin significantly stimulated PCV2 replication in vivo. Immunological reaction in atovastatin‐treated mice was also significantly enhanced during PCV2 infection. Atovastatin also enhanced PCV2‐induced illness in mice. The results of this study will provide new insight into the role of atovastatin in PCV2 infection.     

扁蒴藤素对急性实验性炎症的作用及其机制研究

目的 研究扁蒴藤素对急性实验性炎症的作用及其机制。方法 用巴豆油致小鼠耳肿,角叉菜胶致小鼠足肿,醋酸诱发小鼠毛细血管通透性增高,角叉菜胶致大鼠腹膜炎模型,观察扁蒴藤素对小鼠耳肿、足肿、毛细血管通透性增高以及对大鼠腹膜炎渗出液中的白细胞计数、蛋白质含量、一氧化氮(NO)含量、β-N-乙酰氨基葡萄糖苷酶(NAG)释放、丙二醛(MDA)生成、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性的影响。结果 扁蒴藤素ip 0.156～0.625 mg·kg~(-1)或im 1～4 mg·kg~(-1)明显抑制小鼠耳肿和足肿(P<0.05);im 2～4 mg·kg~(-1)明显抑制小鼠毛细血管通透性增高(P<0.05);im 1～2 mg·kg~(-1)抑制大鼠腹膜炎白细胞渗出、蛋白质渗出及NAG释放,降低NO含量,抑制MDA生成,增强SOD及CAT活性。结论 扁蒴藤素有明显的抗炎作用;抗炎作用可能与其抑制NO生成、清除氧自由基、抗脂质过氧化、稳定溶酶体膜有关。     

Effect of morphine and naloxone on priming-induced audiogenic seizures in BALB/c mice.

1 Morphine (1-200 mg/kg s.c.) reduced the incidence and prolonged the latency of priming-induced audiogenic siezures in a dose-dependent manner. 2 This effect was reversed by naloxone (1 and 2 mg/kg) although naloxone was itself inactive. 3 This priming-induces seizure model may be useful in the study of tolerance and physical dependence.