地塞米松对哮喘豚鼠肺组织嗜酸细胞bcl-2表达的影响及意义

目的 研究哮喘豚鼠肺内不同密度嗜酸细胞（Eos）凋亡与bcl-2 mRNA表达的关系及地塞米松（DM）对它们的影响。方法 应用DM干预哮喘豚鼠,分离哮喘豚鼠支气管肺泡灌洗液中不同密度Eos,以TUNEL法检测细胞凋亡,以原位杂交检测bcl-2 mRNA表达。结果 哮喘组Eos凋亡率较正常组明显降低（P〈0．01）,应用DM后均显著增加（P〈0．01）。正常豚鼠Eos可检测到bcl-2 mRNA表达,不同密度Eos表达无显著差异（P〉0．05）。哮喘组bcl-2mRNA明显增加,应用DM后其表达明显减少。结论凋亡调节的缺失是导致组织及血中Eos增多的重要原因,bcl-2参预了哮喘Eos凋亡的调节。DM可促进哮喘肺组织中的Eos细胞凋亡,bcl-2可能是DM调节Eos细胞凋亡的重要途径之一。     

Rapid accumulation of eosinophils in lung lesions in guinea pigs infected with Mycobacterium tuberculosis

Guinea pig eosinophils were positively identified in bronchoalveolar lavage populations and in the lung granulomas of Mycobacterium tuberculosis-infected guinea pigs. It is possible that the rapid influx of these cells, and their subsequent degranulation during acute pulmonary tuberculosis, may play a key role in the susceptibility of this animal model.     

Further definition of the encephalitogenic region for guinea pigs.

The effect on encephalitogenicity of using a serinyl substitution for the glutaminyl group in the peptide ser arg phe ser trp gly ala glu gly gln arg is reported. We conclude from these results that the function of the glutaminyl residue is assisting this peptide to produce allergic encephalomyelitis in guinea pigs is as a hydrogen donor-receptor.     

Airway eosinophils from actively sensitized guinea pigs exhibit enhanced superoxide anion release in response to antigen challenge.

Antigen challenge of actively sensitized guinea pigs produces airway eosinophilia, airway hyperreactivity, and late-phase bronchoconstriction. The recruited eosinophils are thought to be important cells in the development of the airway hyperreactivity and the late-phase bronchoconstriction. However, the functional abilities of these eosinophils have not been determined in response to antigen challenge. The purpose of this study was to describe the characteristics of superoxide anion release from airway eosinophils obtained 24 h after ovalbumin challenge of actively sensitized guinea pigs. Eosinophils were collected by bronchoalveolar lavage. The total bronchoalveolar lavage eosinophil count was 17- to 27-fold greater in sensitized, ovalbumin-challenged guinea pigs (9.30 +/- 0.11 x 10(6)/guinea pig) than in unsensitized guinea pigs (0.35 +/- 0.07 x 10(6)/guinea pig) or sensitized, saline-challenged guinea pigs (0.56 x 10(6)/guinea pig; n = 2). The increase in eosinophils was due to increased lavage leukocyte count and increased eosinophil differential. Eosinophils were isolated on a Percoll-plasma discontinuous gradient. Two populations of eosinophils were collected, one at the 1.093 g/ml gradient step and one at the 1.107 g/ml gradient step. Unstimulated or phorbol myristate acetate (PMA)-stimulated superoxide anion release was measured by the reduction of ferricytochrome c. Unstimulated superoxide anion release from both eosinophil populations of challenged guinea pigs (4.50 +/- 2.37 and 4.07 +/- 1.48 nmol from 1.093 and 1.107 g/ml eosinophils, respectively) was 6- to 7-fold greater than superoxide anion release from eosinophils of control guinea pigs (0.74 +/- 0.43 and 0.56 +/- 025 nmol from 1.093 and 1.107 g/ml eosinophils, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of adenosine on guinea pig pulmonary eosinophils

Extracellular adenosine has pharmacological activity on a wide variety of cell types and may play an important role as an inflammatory modulator with both pro- and anti-inflammatory activities. These studies examine the effects of adenosine on guinea pig pulmonary eosinophils. Adenosine alone did not directly induce superoxide (O ₂ ^– ) production. Pretreatment with adenosine primed the O ₂ ^– response of guinea pig pulmonary eosinophils following the addition of 1 or 10M plateletactivating factor (PAF). Priming was seen at adenosine concentrations greater than 1 M and was maximal at 100M. At this maximal dose, adenosine priming increased the O ₂ ^– response to 1M and 10M PAF by 86% and 51%, respectively. Priming by adenosine was not seen when ionomycin or phorbol myristate acid (PMA) were used as agonists. In fura-2 loaded eosinophils, the addition of 100 M adenosine resulted in a small but significant rise in intracellular calcium of 54.4 ±9.2 nM above baseline. In contrast, similar adenosine concentrations had no effect on cytosolic calcium levels in guinea pig neutrophils. These data demonstrate a pro-inflammatory role for adenosine in elicited guinea pig pulmonary eosinophils.     

Cytomegalovirus-induced mononucleosis in guinea pigs.

The effects of cytomegalovirus (CMV) infection on hematopoietic and lymphoid tissues were studied in guinea pigs. Blood parameters, histopathology, and virus distribution in the bone marrow, spleen, lymph nodes, and thymus were assessed during primary nonlethal acute and chronic guinea pig CMV infection. Transient hematological changes comparable to those seen in human CMV mononucleosis were observed during acute infection. These included anemia and leukocytosis with atypical lymphocytes. Splenomegaly and stimulation of spleen and lymph node T- and B-cell areas were also noted. These changes occurred at the peak of virus recovery from all tissues tested, as well as from macrophages and B- and T- cell-enriched spleen subpopulations. Virus was cleared rapidly from blood and bone marrow; blood counts, spleen size, and histology returned to normal within 1 month after virus inoculation. However, guinea pigs failed to eliminate the virus completely from lymphoid tissues, since virus persisted in splenic macrophage and B-lymphocyte-enriched populations during chronic infection. The data suggest that CMV-infected mononuclear cells play a role in the establishment of generalized acute infection and virus persistence.     

Sensitization of guinea pigs to levamisole.

Levamisole, an anti-helminthic drug used also as an immunostimulating agent, has been found to be a potent skin sensitizer in experimental animal models. Sensitization is associated with marked T-lymphocyte proliferation in the draining lymph node. It is suggested that immunostimulation through increase in the T-lymphocyte population could be a function of the strong sensitization induced by this compound.     

Effects of NZ-107 on bronchoconstriction in guinea pigs.

The effect of 4-bromo-5-(3-ethoxy-4-methoxybenzylamino)-3(2H)-pyridazinone (NZ-107) on bronchoconstriction in guinea pigs was studied (1). The antigen-induced bronchoconstriction was studied in guinea pigs which had been passively sensitized by intravenous injection of antiserum containing anti-benzylpenicilloyl bovine-gamma-globulin IgE antibody. The sensitized guinea pigs were divided into two groups; one group was pretreated with metyrapone (11 beta-hydroxylase inhibitor in glucocorticoid metabolism) and the other with saline. The antigen-induced bronchoconstriction in the metyrapone-treated animals was more severe than that in the saline-treated animals. The asthmatic respiratory changes, in terms of prolongation of the ratio between expiration and inspiration, was also dramatically increased. NZ-107 at doses of 25 and 50 mg/kg significantly inhibited antigen-induced bronchoconstriction in both the saline-and metyrapone-treated animals. NZ-107 showed a tendency to inhibit accelerated severe asthmatic respiration more strongly in metyrapone-treated animals than in those treated with saline. Salbutamol inhibited antigen-induced bronchoconstriction in saline-treated animals, but its efficacy decreased in metyrapone-treated animals. Unlike salbutamol, prednisolone and hydrocortisone showed the reverse effect, inhibiting bronchoconstriction in metyrapone-but not in saline-treated animals. Sodium cromoglycate inhibited antigen-induced bronchoconstriction in both saline- and metyrapone-treated animals (2). When a subthreshold dose of platelet-activating factor was injected into guinea pigs, airway responsiveness against histamine was clearly increased. NZ-107 at a dose of 0.2 mg/kg i.v. inhibited PAF-induced airway hyperreactivity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Taste-aversion learning in infant guinea pigs.

Infant guinea pigs were hand-fed a 10% sucrose solution and poisoned after delays of 0 min, 30 min, or 24+ hr. Subjects in the first 2 groups showed significant sucrose aversions when tested more than a month later. No significant difference existed between the 0- and 30-min groups; no deficiency in this type of learning was evident even in neonates. All 3 groups showed a lower sucrose preference if first exposed at ages 0-6 days than at 7-11 days. Evidently exposure to sucrose at the earlier ages was less effective in reducing later neophobia to sucrose; although the youngest animals had no evident deficiency in learning aversions, they may have been deficient in learning "safety".     

Antibody-mediated adherence of rat eosinophils to schistosomula of Schistoma mansoni in vitro.

Eosinophils from the peritoneal washings of normal rats adhered to live or formalin-fixed schistosomula of Schistosoma mansoni in vitro, in the presence of heat-inactivated serum from infected rats. Eosinophil adherence caused permeability changes in the schistosomula as revealed by 51Cr release and methylene blue uptake. The serum factor which mediated adherence resided in the 7S fraction after Sephadex G-200 gel filtration. Protein A from Staphylococcus aureus which binds specifically to the Fc piece of IgG inhibited adherence, thereby demonstrating that IgG was the antibody responsible for this reaction and that the Fc portion was the site of interaction between eosinophil and antibody; rat eosinophils were shown to possess Fc receptors. The antibody mediating adherence reached high titres in the sera of rats 5-8 weeks after exposure to 500 cercariae, but thereafter there was a gradual decline in titre. Surface membrane from adult S. mansoni inhibited adherence, indicating the presence of cross-reacting antigens in adult worms and schistosomula.     

Effect of immunosuppression on Rickettsia rickettsii infection in guinea pigs.

The role of the immune response in the pathogenesis of Rickettsia rickettsii infection in guinea pigs was investigated by immunosuppression, using antilymphocyte serum. Twenty guinea pigs were inoculated with R. rickettsii, Sheila Smith strain, on day 0. Fifteen animals received antilymphocyte serum on days --1, 0, 2, 4, and 6. Five animals received normal rabbit serum on the same schedule. At necropsy, specimens were collected for histological examination, rickettsial immunofluorescence, rickettsial titration, and antirickettsial antibody titration. All normal rabbit serum recipients and 12 of 15 antilymphocyte serum recipients developed typical disease. Comparison of animals in terminal stages of disease revealed the same clinical course and gross lesions, but differing rickettsial burden and cellular response. Immunosuppressed animals had higher titers of splenic rickettsiae and greater numbers of immunofluorescent rickettsiae. Thus, although antibody was undetectable in both groups, there appeared to be an inhibition of antirickettsial immunity. Microscopic vasculitis was similar quantitatively, but differed qualitatively, with immunocompetent animals having the typical monouclear/lymphocytic inflammation and immunosuppressed animals having neutrophilic predominance. This study demonstrates that immunopathological mechanisms are not necessary for the pathogenesis of experimental Rocky Mountain spotted fever. The rickettsiae themselves seem capable of causing cellular and tissue damage.     

Mitogenic factor from chronically infected guinea pigs.

A lymphokine produced by antigen stimulated lymphocytes, induces blastogenesis in cultures of lymphocytes which are not sensitive to the specific antigen. The in vitro production of this factor (MF) was accomplished utilizing peritoneal exudate (PE) cells from Coccidioides immitis infected guinea pigs. Production of MF by lymphoid cultures paralleled skin test reactivity of the donor animal. Removal of adherent cells from the PE population did not decrease the production of MF; conversely, a more significant production of MF was effected by the adherent cell depleted populations. Maximal production of MF was achieved at non-adherent cell concentrations from 4 X 10(6) to 8 X 10(6) cells/ml. Cell concentrations below 4 X 10(6)/ml produced material which inhibited DNA synthesis in test cultures. MF was separated from the inhibitory substance(s) by column chromatography of the crude preparations on Sephadex G-75. Inhibitor(s) eluted in the void volume (VO), and the MF eluted in an effluent volume (Ve) which was greater than the total bed volume (Vt) suggesting that MF is adsorbed by Sephadex beads.     

The effect of formoterol on the late asthmatic phenomena in guinea pigs.

We investigated the effects of formoterol, a new, long-acting, selective beta 2-adrenoceptor agonist, on the antigen-induced late asthmatic response (LAR) and airway inflammation in guinea pigs. Animals were sensitized by exposure to aerosolized ovalbumin (2% in saline). After antigen challenge, preceded by administration of an H1-receptor antagonist, specific airway conductance was measured with a two-chambered whole-body plethysmograph. An aerosolized solution of formoterol, isoproterenol, or saline was inhaled 15 minutes before challenge. Bronchoalveolar lavage (BAL) was performed 24 hours after challenge. The provocative concentrations of histamine required to decrease specific airway conductance by 50% were obtained before challenge, at 24 hours, and at 72 hours after challenge. The LAR (52.7% +/- 7.7% of the baseline; p less than 0.02) was observed 6 to 8 hours after antigen challenge. An increased cellular influx in BAL (mainly eosinophils and macrophages) and an increased bronchial responsiveness to histamine occurred 24 hours after antigen challenge. Formoterol completely inhibited the LAR and the cellular increase in BAL; however, isoproterenol failed to prevent either the cellular infiltration or the LAR. Formoterol also decreased the antigen-induced increase in bronchial reactivity. These findings suggest that formoterol has inhibitory effects on the underlying inflammatory processes in antigen-induced asthma in addition to prolonged bronchodilation.     

Chlamydial pneumonitis induced in newborn guinea pigs.

One- to three-day-old guinea pigs were inoculated intranasally with the chlamydial agent of guinea pig inclusion conjunctivitis. Physical signs of infection included a marked increase in respiration rate on days 5 to 10 of infection and radiographic evidence of pneumonia on day 6. When animals were killed at various times after infection and lung tissue was examined by histopathology, evidence of pneumonia was found beginning on day 4 and lasting as long as day 12, with maximal pathological changes on days 6 to 8. The pneumonia was generally unilateral and consisted of an acute inflammatory component in the bronchioles with granulocytes in both the lumen and the wall of the bronchioles and an interstitial and intra-alveolar mononuclear infiltrate in the parenchyma of the lung. Chlamydial antigen was detected in the bronchial epithelial cells by immunoperoxidase staining, and the guinea pig inclusion conjunctivitis organism was isolated from lung tissue on days 6 to 9. No other significant bacteria were isolated from lung tissue or seen on gram stains of lung sections. Both immunoglobulin M and immunoglobulin G serum antibodies to the guinea pig inclusion conjunctivitis agent were detected as early as day 8 and reached peak levels on day 12. The infection was apparently self-limiting. This model presents the opportunity to investigate pathophysiological and immunological aspects of chlamydial respiratory infections in a neonatal animal.     

治喘贴对实验豚鼠嗜酸粒细胞凋亡和对白细胞介素-5的影响

目的　研究治喘贴对卵清蛋白所致实验豚鼠哮喘体内嗜酸粒细胞 (EOS)凋亡及对白细胞介素 (IL 5 )的调节作用。方法　将实验动物随机分为正常对照组、哮喘模型组、代温灸膏治疗组、治喘贴治疗组。经外贴治疗 18d ,收集支气管肺泡灌洗液 (BALF)并采集心脏血 ,采用流式细胞仪、免疫组织化学 (TUNEL)和酶联免疫吸附 (ELISA)法分析血中EOS凋亡和BALF中EOS凋亡数及IL 5含量。结果　哮喘豚鼠血和BALF中EOS凋亡数、IL 5含量均高于正常对照组动物 (P均 <0 .0 1) ,治喘贴治疗豚鼠IL 5和EOS均明显低于哮喘模型组 (P均 <0 .0 1)。结论　治喘贴能促进哮喘豚鼠体内EOS凋亡 ,并降低IL 5的水平 ,从而改善哮喘模型豚鼠的气道变态性炎症反应。