Sensitized Guinea Pig Lung Research Articles

The Effect of Natural Adjuvants on Pathological Changes in Sensitized Guinea Pig Lungs

Background:Anti-inflammatory effect of natural adjuvants has been reported. Lung inflammation is the most characterized pathological feature in asthma.Objectives:The effects of three natural adjuvants (PC, G2, and G2F registered as a patent in the Iranian Patent Office) on sensitized guinea pigs lungs were examined in the present study.Materials and Methods:Lung pathological changes were examined in control and five groups of randomly divided guinea pigs including: sensitized animals (S, receiving normal saline, 0.5 ml i.p.); sensitized animals treated with adjuvant PC; G2F (0.1 ml i.p. for both cases); G2 (0.4 ml i.p.); and PC + G2 (receiving both PC and G) adjuvants (twice a week for 4 weeks for all groups). Sensitization of animals was done by injection and inhalation of ovalbumin (OA).Results:All pathological changes in S group including the eosinophil infiltration (scoring 3.28 ± 0.28), lymphocyte infiltration (2.82 ± 0.26), local epithelial necrosis (2.71 ± 0.47) and mucosal plug (2.75 ± 0.37) were significantly higher than control group (0.64 ± 0.18, 1.36 ± 0.24, 0.36 ± 0.18 and 0.28 ± 0.18 for eosinophil infiltration, lymphocyte infiltration, epithelial necrosis and mucosal plug respectively, P < 0.001 for all cases). Treatment with all adjuvants improved all pathological changes significantly (P < 0.05 to P < 0.001).Conclusions:These results indicate preventive effects of all natural adjuvants (especially G2) on pathological changes of the lung in sensitized guinea pigs.

Measurement of leukotrienes in sensitized guinea pig lung perfusate after antigen challenge by high performance liquid chromatography (HPLC)

Measurement of leukotrienes in sensitized guinea pig lung perfusate after antigen challenge by high performance liquid chromatography (HPLC)

Investigation Into the Mechanism of Anti-Asthmatic Action of Moringa oleifera

ABSTRACT.We have studied the possible mechanism of the antiasthmatic action of Moringa oleifera seed kernel ethanolic extract (EXMO, 400 mg/kg). EXMO produced an increase in the Preconvulsion Dyspnea time induced by histamine and acetylcholine aerosol, a significant reduction in the elevated eosinophil and monocyte counts in the Broncho-Alveolar Lavage fluid of sensitized guinea pigs, reduction in the paw edema volume as compared to the control rats, and decrease in the elevated histamine release from the sensitized guinea pig lungs. The pD2 values of histamine in tracheal chain and taenia coli were significantly greater and that in lung strip was lower in the sensitized animals and treatment with EXMO significantly decreased pD2 values in all three preparations. Our data suggest inhibition of the immediate hypersensitive reaction, histamine release, and the infiltration of various inflammatory cells as possible antiasthmatic mechanisms of action.

Inhibition of Nitric-Oxide Synthase Enhances Antigen-Induced Contractions and Increases Release of Cysteinyl-Leukotrienes in Guinea Pig Lung Parenchyma: Nitric Oxide as a Protective Factor

Nitric oxide (NO) in exhaled air is a biomarker of airway inflammation. However, the role of NO in the peripheral lung is not known. The aim of this study was to determine the role of endogenous NO in antigen-induced contractions of ovalbumin (OVA)-sensitized guinea pig lung parenchyma (GPLP). The contraction in this in vitro model of the peripheral lung closely resembles the corresponding response in human airways. Cumulatively increasing concentrations (10-10,000 microg/l) of OVA induced concentration-dependent contractions of the GPLP that were enhanced by the NO synthase (NOS) inhibitors N(omega)-nitro-L-arginine (L-NOARG; 100 microM), N(omega)-monomethyl-L-arginine (100 microM), N(omega)-nitro-L-arginine methyl ester (100 microM), and N-(3-(aminomethyl)benzyl)acetamidine (1400W; 1 microM). The enhancement induced by L-NOARG was reversed by coadministration with the 5-lipoxygenase inhibitor (R)-2-[4-(quinolin-2-yl-methoxy)phenyl]-2-cyclopentyl acetic acid (BAY x1005; 3 microM), whereas coadministration of L-NOARG with the cyclooxygenase inhibitor indomethacin (10 microM) did not change the effect of L-NOARG alone. L-NOARG (100 microM) did not affect the cumulative concentration-response relations for either leukotriene (LT) D4 (0.1-100 nM) or histamine (1-30 microM). The NO donor NONOate (0.001-100 microM) was ineffective in GPLP but potently relaxed precontracted guinea pig pulmonary artery. Furthermore, L-NOARG enhanced the release of LTE4 and decreased the release of prostaglandin E2 induced by OVA. In conclusion, endogenous NO exerts an inhibitory effect on antigen-induced contractions in the peripheral lung. The action of NO apparently involves inhibition of the release of mediators rather than direct relaxation of airway smooth muscle. The findings support the belief that endogenous NO has a protective anti-inflammatory effect in the airways.

Effects of levocabastine on lipid mediator release from guinea pig lung fragments.

The effects of levocabastine, a novel histamine H1-receptor antagonist, on lipid mediator release induced by antigen-antibody reaction from actively sensitized guinea pig lung fragments were studied. Levocabastine dose-dependently inhibited the release of leukotriene C4 from guinea pig lung fragments induced by antigen. A significant effect was observed with levocabastine at a concentration of 10(-4) M. On the other hand, levocabastine produced no effect on the release of leukotriene E4 or thromoboxane B2. From these findings, it was concluded that levocabastine may be useful for relieving the nasal obstruction in allergic rhinitis caused by inhibition of leukotriene C4 release.

Effects of baicalein on prostanoid generation from the lung and contractile responses of the trachea in guinea pig.

Effects of baicalein on release of slow reacting substance of anaphylaxis (SRS-A) or leukotriene (LT) from the sensitized guinea pig lung after antigen challenge and tonus of guinea pig tracheal muscles were studied. Baicalein inhibited release of SRS-A from sensitized guinea pig lung after antigen challenge. High-performance liquid chromatography (HPLC) analysis revealed that released SRS-A consisted to LTC4 and D4. Baicalein also reduced release of LTC4 and D4 from the sensitized lung after antigen challenge. Baicalein relaxed the isolated guinea pig tracheal smooth muscle contracted by LTD4, carbachol or histamine. However, this compound produced a contraction when the tracheal muscle was contracted by prostaglandin F2 alpha(PGF2 alpha). This contraction by baicalein was abolished by pretreatment with indomethacin, a cyclooxygenase inhibitor. Baicalein elicited a relaxation in the normal non-sensitized preparation but a contraction in the tissue isolated from actively sensitized guinea pig in 4 among 7 cases. Baicalein also produced a contraction in the trachea pretreated with phorbol dibutyrate and contracted by carbachol, which was eliminated after treatment with indomethacin. The results suggest that baicalein exerts action via, at least, two different mechanisms, the inhibition of releasing SRS-A (LTs) and direct relaxing effects on the trachea. Besides, baicalein seems to produce contraction under certain conditions, which may involve stimulation of the cyclooxygenase pathway.

Alteration of eicosanoid production in the sensitized guinea pig lung by CS-518

The effects of CS-518 (sodium 2-(1-imidazolymetthyl)-4,5-dihydrobenzo [b]thiophene-6-carboxylate), a thromboxane A 2 Antigen challenge enhaned the production of thromboxane A 2 as well as histamine and peptide leukotrienes in lung fragments. Exogenous leukoriene D 4 also stimulated significant thromboxane A 2 production int he non-sensitized lung in vitro. CS-518 was effective in preventing the thromboxane A 2 production induced by either antigen or leukotriene D 4, and the IC 50 values were 90 and 7.5 ng/ml (320 and 27 nM), respectively. CS-518 markedly potentiated the production of prostaglandin E 2 and I 2 with slight inhibition of leukotriene formation, but indomethacin significantly stimulated leukotriene production. When CS-518 was administered orally, it induced long-lasting inhibition of thromboxane A 2 production and potentiation of prostaglandin I 2 production in guinea pig lung. Thus, CS-518 not only inhibited thromboxane production but also improved the change in arachidonic acid metabolism in the guinea pig bronchoalveolar tissue during allergic reaction in vivo as well as in vitro, which suggests amelioration of the asthmatic condition.

Effect of Three Novel K+ Channel Openers, Cromakalim, Pinacidil and Nicorandil on Allergic Reaction and Experimental Asthma.

The anti-allergic and anti-asthmatic activities of three potassium (K+) channel openers, cromakalim, pinacidil, and nicorandil, were investigated. 1) Forty-eight-hour homologous passive cutaneous anaphylaxis (PCA) in mice was not affected by cromakalim, pinacidil, or nicorandil. Ketotifen significantly inhibited the reaction. 2) Antigen-induced histamine release from sensitized guinea pig lung tissue was not affected by cromakalim, pinacidil or nicorandil (except for 10(-4) M nicorandil). Salbutamol inhibited the release of histamine. 3) Histamine, serotonin and LTC4-induced vasculitis in rat back skin was not affected by any of these three K+ channel openers. 4) Antigen-induced constriction of isolated sensitized guinea pig tracheal muscle was relaxed by each of the K+ channel openers. 5) Constrictions of isolated guinea pig tracheal muscle caused by high potassium, histamine, LTC4, or U-46619 were clearly relaxed by each of the three K+ channel openers. 6) Increases of airway resistance caused by histamine, LTD4, or U-46619 in guinea pigs in vivo were inhibited by administration of each of the three K+ channel openers. 7) Experimental asthma caused by the IgE antibody and antigen system in guinea pigs was inhibited by each of the three K+ channel openers.

Effects of Qing-Fei-Tang on the Airway Inflammation and Clearance

Qing-Fei-Tang, a Chinese blended medicine, inhibited the release of slow reacting substance of anaphylaxis (SRS-A) from passively sensitized guinea pig lung after antigen challenge. Qing-Fei-Tang also suppressed the chemiluminescence of oxygen radicals when healthy human leukocytes were stimulated by opsonized zymosan. In rabbits, Qing-Fei-Tang increased the output volume and fatty acid contents in respiratory tract fluid. In the bronchitic rabbits, 6 weeks administration of Qing-Fei-Tang restored the decreased amount of saturated fatty acid in the sputa, and histological examinations revealed an amelioration of the inflammation of lung tissues. In pigeons, Qing-Fei-Tang facilitated tracheal mucociliary transport. Accordingly, Qing-Fei-Tang seems to exert effectiveness via its multiple mechanisms.

特異的Ｔｈｒｏｍｂｏｘａｎｅ（ＴＸ）Ａ２合成酵素阻害剤（Ｅ）‐３‐〔ｐ‐（１Ｈ‐ｉｍｉｄａｚｏｌ‐１‐ｙｌｍｅｔｈｙｌ）ｐｈｅｎｙｌ〕‐２‐ｐｒｏｐｅｎｏｉｃ ａｃｉｄ（ＯＫＹ‐０４６）の抗アルルギー作用 （第１報） Ｉ型アレルギー反応に対する作用

We studied the effects of OKY-046 on type I allergic reactions. OKY-046 (100 mg/kg) given orally suppressed antigen-induced bronchoconstriction and TXB2 generation in broncho alveolar lavage fluid in rats passively sensitized with anti-DNP-As monoclonal IgE. At the dose of 30 mg/kg given intraduodenally, it also inhibited antigen-induced bronchoconstriction in guinea pigs passively sensitized with anti DNP-As serum and actively sensitized with ovalbumin. However, aspirin (30 mg/kg) didn't suppressed them significantly. Azelastine (10 mg/kg) inhibited bronchoconstriction in passively sensitized rats and actively sensitized guinea pigs. In 48 hour homologous PCA reactions of rats and mice, oral administration of OKY-046 (300 mg/kg) and tranilast (100 mg/kg) suppressed the extravasated dye in the skin. OKY-046 decreased histamine release from passively sensitized rat peritoneal exudate cells. There was no effect of OKY-046 on SRS-A and leukotriene release from actively sensitized guinea pig lungs and passively sensitized rats. In conclusion, we think that OKY-046 should be an useful asthmatic drug or anti-allergic drug by oral administration.

Histological Study of Mast Cells in the Actively Sensitized Guinea Pig Lung and after Challenge: Effect of a Corticosteroid

Although mast cells are sometimes considered to play a minor role in hypersensitivity reactions, we used a histological method to show the modifications in the guinea pig lung mast cell population in the course of such reactions. We sensitized guinea pigs with ovalbumin and studied the effect of the challenge with and without corticosteroid treatment. We observed that the mast cell count was not modified after sensitization but was decreased after challenge. Twenty-four hours after challenge, the number of mast cells returned to the control value, indicating a renewal of the mast cell pool. A second challenge, 1 week after the first, did not provoke the same mast cell degranulation, suggesting a non-responsiveness to aerosol antigen. Betamethasone dipropionate treatment protected mast cells against challenge: in treated guinea pigs, mast cell degranulation was prevented, and we did not observe any change in mast cell count after challenge. The present study was useful to show an effect of corticosteroids on mast cell degranulation in immediate hypersensitivity reactions in vivo.

Anti-asthmatic activity of newly synthesized calcium antagonists: 2-n-butyl-1 (N-methyl-n-[2-(N',N'-dimethylamino)ethyl]amino) -5,6-methylenedioxy-indene and -indane.

The anti-asthmatic activity of the newly synthesized methylenedioxyindene (MDI) derivatives, 2-n-butyl-1 (N-methyl-N-[2-(N', N' -dimethylamino)ethyl]amino)-5, 6-methylenedioxy-indene (MDI-C) and -indane (MDI-D), were investigated in vitro and in vivo in guinea pigs. The in vitro pharmacological activity of both derivatives was compared to that of 8-(diethylamino)octyl-3,4, 5-trimethyoxybezoate hydrochloride. All three agents caused a concentration-dependent inhibition of the antigen-induced contraction of sensitized guinea pig tracheal smooth muscle. In histamine and leukotriene D4-induced contractions of guinea pig tracheal smooth muscle, each agent showed clear antagonistic actions. Additionally, all three agents demonstrated potent calcium antagonistic actions via inhibition of guinea pig tracheal smooth muscle contractions caused by CaCl2 in a high potassium and Ca-free medium and by compound 48/80 in a solution of ethylene glycol bis(beta-aminoethylether)-N,N,N',N'-tetraacetic acid in a contained Ca-free medium. MDI-C and MDI-D inhibited the antigen-induced release of histamine and slow reacting substance of anaphylaxis from sensitized guinea pig lung tissue. Lastly, both MDI is clearly inhibited asthmatic respiratory disorders without affecting blood pressure in guinea pigs.

Identification of leukotriene B 4 as the neutrophil chemotactic factor released by antigen challenge from passively sensitized guinea pig lungs

Neutrophils are prominent in some IgE-mediated allergic reactions and may contribute to the pathophysiology of immediate hypersensitivity. Antigen challenge of fragments of guinea pig lung tissue that were passively sensitized with IgE or IgG antibody evoked the release of neutrophil chemotactic activity (NCA) in parallel with histamine. The NCA released from lung tissue by both IgG- and IgE-dependent stimulation coeluted from a column of Sephacryl S-300 with synthetic leukotriene B 4 (LTB 4). The NCA in eluates from the Sephacryl S-300 column contained LTB 4, as determined by high-performance liquid chromatography and specific radioimmunoassay, in quantities that accounted for the observed chemoattractant activity in the eluates. Furthermore, the NCA of supernatants from antigen-challenged lung fragments was reduced by a mean of 80% after absorption with a monoclonal antibody to LTB 4. LTB 4 thus constitutes the major functional constituent of NCA released after anaphylactic challenge of IgE- and IgG-sensitized guinea pig lung tissue.

代謝臓器としての肺

Lung is not only a respiratory organ, but also a metabolic organ. Pulmonary vascular beds are extremely wide and this helps the lung to metabolite various vasoactive substances and to perform the gas exchange. Lungs can metabolite or inactivate PGE2, PGF2α, LTC4, LTD4, LTE4, serotonin, acetylcholine, bradykin, histamine and norepinephrine, and can produce histamine, serotonin, PAF, LTs, thromboxane A2 and various PGs. Percentage inactivation of PGs and LTs are closely dependent to the width of pulmonary vascular beds. The percentage inactivation showed a marked decrease by increasing the dose of administered vasoactive substances, and also showed a marked decrease by clumping the left pulmonary artery trunk or by infusing glass beads (100μ of diameter) into the pulmonary artery.Chemical mediators, histamine and SRS-A can interact and regulate the release of other chemical mediator, and PAF accelerates the release of histamine, SRS-A, LTC4 from passively sensitized guinea pig lung tissue following the antigen challenge.It is well known that cigarette smoking has diverse effects not only on the airway system but also on the pulmonary and systemic circulation.

Effect of OKY-046, a new thromboxane A 2 synthetase inhibitor, on experimental asthma in guinea pigs

The effect of OKY-046, a newly synthetized thromboxane A 2 (TxA 2) synthetase inhibitor, on IgE mediated experimental asthma in guinea pigs was investigated. Indomethacin, a cyclooxygenase inhibitor, and tranilast (N-5′), a potent anti-allergic agent, were used as comparative drugs. OKY-046 clearly improved asthmatic respiratory disorders in guinea pigs. Whereas indomethacin had no effect on the changes of asthmatic respiration, tranilast significantly inhibited the changes. OKY-046 inhibited the in vitro antigen-induced contraction of sensitized guinea pig lung parenchyma. This antigen-induced contraction was also inhibited by tranilast, but not by indomethacin. OKY-046 inhibited the contractions of lung parenchyma caused by leukotriene C 4, D 4 and E 4 (LTC 4, LTD 4 and LTE 4), but not by histamine. Indomethacin showed a biphasic action on the contractile responses caused by histamine and LTD 4 Consequently, contractions due to either agonist at low concentrations were inhibited by indomethacin, but those at high concentrations were enhanced. Tranilast inhibited the contraction of lung parenchyma induced by a low concentration of LTD 4 but not that produced by histamine. Moreover, OKY-046 inhibited an elevation of concentration of thromboxane B 2 (TxB 2) in guinea pig lung perfusate after infusion of LTC 4 but did not affect the elevation of 6-keto-PGF 1α. OKY-046 had no effect on the antigen-induced release of histamine but it inhibited the release of the slow reacting substance of anaphylaxis (SRS-A) from sensitized chopped lung tissues. Indomethacin at a high concentration inhibited the release of histamine but did not affect the release of SRS-A. Tranilast clearly inhibited the release of both mediators. These results suggest that OKY-046 inhibits IgE mediated experimental asthma in guinea pigs and that its main mechanism is related to the inhibition of LT induced contraction of airway smooth muscle and the release of SRS-A from lung tissues.

Enzymatic Study to Characterize the Slow Reacting Substance of Anaphylaxis (SRS-A) and Leukotrienes

Slow reacting substance of anaphylaxis (SRS-A) has been shown to be one of the major mediators in hypersensitive reactions and to be composed of leukotriene (LT) C4, LTD4 and LTE4. In the present study, we examined the properties of SRS-A released from sensitized guinea pig lungs by antigen and SRS released from rat peritoneal exudate celis and from human leucocytes by ionophore A23187 (0.5 and 0.2 μg/ml, respectively). By the incubation with SRS-A, SRS and LTs with arylsulfatase (type V) in pH 5.7 buffered solution at 37°C for 30 min, SRS-A and LTD4 were greatly inactivated and rat SRS was slightly inactivated, but human SRS and LTC4 were not inactivated at all. The same results were obtained when aminopeptidase was used in place of arylsulfatase. Moreover, when SRS-A, LTC4 and LTD4 were incubated with 0.02 mg/ml of γ-glutamyltranspeptidase (γ-GTP) pH 8.0 buffered solution at 37°C for 30 mm, the activities of SRS-A and LTD4 were slightly decreased, but those of SRS and LTC4 were obviously potentiated. On the other hand, incubation with a large amount of γ-GTP (0.2 mg/ml) a dose at which this enzyme preparation showed clear aminopeptidase activity, SRS-A, SRS, LTC4 and LTD4 were obviously inactivated. In addition, we found a peak of LTD4 in guinea pig SRS-A, that of LTC4 in human SRS, and that of LTC4 in rat SRS on high performance liquid chromatograms. From these results, we demonstrated that guinea pig lung SRS-A is mainly composed of LTD4, human leukocyte SRS is mainly LTC4, and rat peritoneal SRS is composed of both LTC4 and LTD4. The inactivation of LTD4 and SRS-A by arylsulfatase may be due to aminopeptidase contamination in the enzyme preparation.

Enzymatic study to characterize the slow reacting substance of anaphylaxis (SRS-A) and leukotrienes.

Slow reacting substance of anaphylaxis (SRS-A) has been shown to be one of the major mediators in hypersensitive reactions and to be composed of leukotriene (LT) C4, LTD4 and LTE4. In the present study, we examined the properties of SRS-A released from sensitized guinea pig lungs by antigen and SRS released from rat peritoneal exudate cells and from human leucocytes by ionophore A23187 (0.5 and 0.2 microgram/ml, respectively). By the incubation with SRS-A, SRS and LTs with arylsulfatase (type V) in pH 5.7 buffered solution at 37 degrees C for 30 min, SRS-A and LTD4 were greatly inactivated and rat SRS was slightly inactivated, but human SRS and LTC4 were not inactivated at all. The same results were obtained when aminopeptidase was used in place of arylsulfatase. Moreover, when SRS-A, LTC4 and LTD4 were incubated with 0.02 mg/ml of gamma-glutamyltranspeptidase (gamma-GTP) pH 8.0 buffered solution at 37 degrees C for 30 min, the activities of SRS-A and LTD4 were slightly decreased, but those of SRS and LTC4 were obviously potentiated. On the other hand, incubation with a large amount of gamma-GTP (0.2 mg/ml) a dose at which this enzyme preparation showed clear aminopeptidase activity, SRS-A, SRS, LTC4 and LTD4 were obviously inactivated. In addition, we found a peak of LTD4 in guinea pig SRS-A, that of LTC4 in human SRS, and that of LTC4 in rat SRS on high performance liquid chromatograms. From these results, we demonstrated that guinea pig lung SRS-A is mainly composed of LTD4, human leukocyte SRS is mainly LTC4, and rat peritoneal SRS is composed of both LTC4 and LTD4. The inactivation of LTD4 and SRS-A by arylsulfatase may be due to aminopeptidase contamination in the enzyme preparation.

Antiallergic Effects of Terfenadine on Immediate Type Hypersensitivity Reactions

Terfenadine dose-dependently inhibited rat homologous PCA (2.5-10 mg/kg, p.o.) and experimentally-induced asthma in guinea pigs (0.5-5 mg/kg, p.o.). Similarly, metabolites I and II dose-dependently inhibited experimentally-induced asthma but their respective potencies were approximately 1/2 and 1/15th that of terfenadine. These results suggest that the metabolites contribute to the antiallergic effects of terfenadine. In ex vivo, terfenadine (5-20 mg/kg, p.o.) also inhibited the release of both antigen-induced histamine and SRS-A from sensitized guinea pig lung samples and that of histamine from rat peritoneal mast cells. Terfenadine dose-dependently increased the cAMP content in rat mast cells and in the lungs; in the latter, the augmented cAMP is associated with an increase in adenylate cyclase activity, but not with the inhibition of phosphodiesterase activity. The above evidence indicates that the inhibitory effects of terfenadine on mediator release from mast cells are in some way related to its antiallergic effects, and that an elevated cAMP content may be effective to enhance mediator release inhibition.

モルモット感作肺組織からのケミカルメディエーターの放出に及ぼすＰＡＦの効果

モルモット感作肺組織からのケミカルメディエーターの放出に及ぼすＰＡＦの効果

Inhibitory Effects of Oxatomide on Intracellular Ca Mobilization, Ca Uptake and Histamine Release, Using Rat Peritoneal Mast Cells

Oxatomide at concentrations of 0.01-10 microM inhibited not only an increase in 45Ca uptake but also the intracellular Ca2+ release induced by compound 48/80 in rat peritoneal mast cells. At higher concentrations, ketotifen or other calcium antagonists caused similar inhibitory effects. However, the inhibitory effect of oxatomide on the 45Ca uptake into rat neonatal heart cells was much weaker than that of verapamil. Through image processing of quin 2-stained mast cells, it was revealed that oxatomide inhibited Ca2+ release from the intracellular store. Although oxatomide alone did not affect cAMP and cGMP contents in sensitized guinea pig lung samples, the drug effectively prevented changes in the nucleotide contents evoked by antigen challenge. These results suggest that the inhibitory effect of oxatomide on histamine release may be caused by a combination of prevention of Ca uptake, which is highly selective toward mast cells; inhibition of Ca2+ release from the intracellular Ca store, and elevation of the cAMP content in mast cells.