ABSTRACT
<p><b>OBJECTIVE</b>To investigate the immunoregulatory effects of pertussis protein on airway inflammatory, IFN-gamma/IL-4 ratio in bronchoalveolar lavage fluids(BALF) and airway hyperresponsiveness (AHR) in the sensitized mice.</p><p><b>METHODS</b>The sensitized mice were reexposed to ovalbumin and the airway response to methacholine injection was monitored. Inflammatory cells and cytokines IFN-gamma/IL-4 ratio in BALF were measured. Lung tissue specimens were collected for histological examination.</p><p><b>RESULT</b>Intramuscular injection or intranasal instillation of pertussis protein inhibited changes in lung resistance and lung dynamic compliance, upregulated IFN-gamma/IL-4 ratio and decreased eosinophil accumulation in a dose-dependent manner. Pathological examination showed that goblet cell hyperplasia and inflammatory cells infiltration in lung tissue were suppressed by pertussis protein.</p><p><b>CONCLUSION</b>Pertussis protein inhibits the inflammation and regulates the function of lungs in asthma mice, suggesting its potential application in treatment of asthma.</p>
Subject(s)
Animals , Male , Mice , Albumins , Asthma , Allergy and Immunology , Therapeutics , Bacterial Proteins , Allergy and Immunology , Pharmacology , Bacterial Toxins , Allergy and Immunology , Pharmacology , Bronchoalveolar Lavage Fluid , Chemistry , Interferon-gamma , Interleukin-4 , Methacholine Chloride , Mice, Inbred ICRABSTRACT
<p><b>OBJECTIVE</b>To determine the inhibitory effects of BIO-1211, a very late antigen-4 (vla-4) antagonist, on bronchoconstriction and neutrophil adhesion in rats.</p><p><b>METHODS</b>For evaluating ovalbumin-induced bronchoconstriction in the sensitized rats, the changes in lung resistance (RL) and lung dynamic compliance (C(dyn)) were determined after antigen challenge. Neutrophils from the rats were used to determine fibronectin and serum-induced cell adhesion. The effect of BIO-1211 on wheezing was determined after inhalation of histamine and acetylcholine in guinea pigs.</p><p><b>RESULT</b>BIO-1211 aerosol at 1, 3 and 10 mg/ml significantly inhibited the changes in lung resistance and lung dynamic compliance after antigen challenge in the sensitized rats in a dose-dependent manner. BIO-1211 at 25, 50, 100 and 200 microgram/ml inhibited the fibronectin-induced neutrophil adhesion by 23.5%, 24.6%, 61.4% and 58.1%, respectively, and serum-induced adhesion by 29.9%, 35.9%, 35.3% and 15.4%, respectively. Inhalation of 10 mg/ml BIO-1211 did not show any protection against histamine and acetylcholine-induced bronchoconstriction.</p><p><b>CONCLUSION</b>BIO-1211 inhibits bronchoconstriction and neutrophil adhesion, which may be associated with its effect against bronchoconstriction in rats.</p>
Subject(s)
Animals , Female , Male , Rats , Administration, Inhalation , Asthma , Drug Therapy , Bronchoconstriction , Physiology , Bronchodilator Agents , Pharmacology , Cell Adhesion , Guinea Pigs , Neutrophils , Cell Biology , Oligopeptides , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To develop a mouse model of acute lung injury induced by cigarette smoke (CS) and to investigate inflammatory changes with the model.</p><p><b>METHODS</b>ICR mice exposed to CS for 20-min, 3/d. Bronchoalveolar lavage fluid (BALF) and lung tissue were harvested at d 0, d 1, d 3 and d 7 after CS exposure. Neutrophil count in BAFL, TNF-alpha and MMP-12 levels, the activity of MPO in lung tissue were determined.</p><p><b>RESULT</b>Neutrophil count in BALF, MMP-12 and MPO levels in lung tissue were increased after CS exposure in a time-dependent manner with a peak at d3. TNF-alpha level sharply increased at d1, and remained high level until d7.</p><p><b>CONCLUSION</b>ICR mice are tolerant and sensitive to CS exposure, which may be used as an appropriate animal model for acute lung injury induced by cigarette smoke.</p>
Subject(s)
Animals , Male , Mice , Acute Lung Injury , Pathology , Bronchoalveolar Lavage Fluid , Cell Biology , Disease Models, Animal , Matrix Metalloproteinase 12 , Metabolism , Mice, Inbred ICR , Smoke , Nicotiana , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
The aim of this study is to investigate the effect of monoammonium glycyrrhizinate (MAG) on lipopolysaccharide (LPS) -induced acute lung injury (ALI) and its anti-inflammatory mechanism in mice. All male ICR mice were randomly divided into six groups: LPS group; control group; MAG 3, 10, and 30 mg x kg(-1) groups; and dexamethasone (DXM) 5 mg x kg(-1) group. Lung dry weight and wet weight percentage and permeability were detected. Neutrophil infiltration in bronchoalveolar lavage fluid (BALF) and lung tissues was detected by cell count and morphological analysis. The levels of TNF-alpha and IL-10 in lung were detected by ELISA. MPO activity was determined followed the specification. MAG induced a decrease in lung wet weight/dry weight ratio, and significantly decreased in total leucocyte number and neutrophil percentage in the BALF, and MPO activity of lung in a dose-dependent manner. Importantly, It could up-regulate the IL-10 level and down-regulate the TNF-alpha level in the lung tissue of ALI mice. These results suggested that the protective effect of MAG in mice on LPS induced ALI was associated with the regulation of TNF-alpha/IL-10 balance, and MAG maybe a potentially treatment for ALI/ARDS.
Subject(s)
Animals , Male , Mice , Acute Lung Injury , Metabolism , Pathology , Anti-Inflammatory Agents , Pharmacology , Bronchoalveolar Lavage Fluid , Cell Biology , Glycyrrhizic Acid , Pharmacology , Interleukin-10 , Metabolism , Leukocyte Count , Lipopolysaccharides , Lung , Pathology , Mice, Inbred ICR , Neutrophils , Pathology , Organ Size , Peroxidase , Metabolism , Protective Agents , Pharmacology , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
<p><b>AIM</b>To establish an antigen-specific asthmatic model of guinea pig induced by protein antigen extracted from Dermatophagoides farinae (Der f), and study the desensitization of dust mite drops (DMD, extracted from Der f) in a dose progressive manner and long-term sublingual administration.</p><p><b>METHODS</b>To sensitize the guinea pigs, the protein antigen emulsified in aluminium hydroxide gel was subcutaneously and intraperitoneally injected. To observe early-phase reaction of asthma, lung resistance (R(L)) and lung dynamic compliance (Cdyn) in the sensitized guinea pigs were determined by intravenously injecting antigen. To observe late-phase reaction of asthma, the sensitized guinea pigs were challenged with aerosolized antigen for 7 days. Subsequently, methacholine (Mch) in a cumulative dose-manner induced-airway hyperreactivity (AHR), inflammatory cells numbers in bronchoalveolar lavage fluid (BALF) and pathological changes of lung tissue were measured in the model. From the first day of sensitization, the guinea pigs in treatment group sublingually received DMD in a dose progressive manner. The model group sublingually received equivalent saline. The normal control group did not receive any treatment.</p><p><b>RESULTS</b>The guinea pigs in model group showed a significant increase in R(L) and decrease in Cdyn, and developed a marked AHR to Mch. The number of total leukocytes and eosinophils increased significantly in BALF. Serious infiltration of eosinophils was observed in pathological section of lung tissue. Compared with model group, DMD treatment group exhibited a significant amelioration for early-phase and late-phase reaction of asthma.</p><p><b>CONCLUSION</b>DMD in a dose progressive manner and long-term sublingual administration displays a significant desensitization on Der f antigen-specific asthmatic reaction. The results provided experimental evidence for clinical therapy.</p>
Subject(s)
Animals , Female , Male , Administration, Sublingual , Airway Resistance , Allergens , Allergy and Immunology , Antigens, Dermatophagoides , Therapeutic Uses , Asthma , Allergy and Immunology , Therapeutics , Bronchoalveolar Lavage Fluid , Cell Biology , Dermatophagoides farinae , Allergy and Immunology , Desensitization, Immunologic , Methods , Eosinophils , Pathology , Guinea Pigs , Leukocyte Count , Lung ComplianceABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of the metabolite of leflunomide, A771726,on proliferation and collagen synthesis of hepatic stellate cell (HSC).</p><p><b>METHODS</b>HSC and Kupffer cells were isolated from the rat liver by collagenase IV and pronase perfusion, and purified by density gradient separation. The effects of A771726 on cell proliferation and collagen synthesis were examined by 3H-thymidine and 3H-proline incorporation assays, respectively. The TGF-beta, TNF-alpha and IL-1 levels in Kupffer cell conditioned medium (KCCM) were determined by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>HSC and Kupffer cells in rat liver were well separated. The KCCM of CCl4-injured rats had significant stimulation effect on proliferation and collagen synthesis of HSC in primary culture. Addition of A771726 (0.001-10 micromol/Lein HSC culture stimulated by KCCM significantly inhibited proliferation and collagen synthesis of HSC. Furthermore, the elevated TGF-beta, TNF-alpha and IL-1 levels in KCCM of CCl4-injured rats were significantly reduced in A771726 treatment groups.</p><p><b>CONCLUSION</b>A771726 has markedly inhibitory effect on proliferation and collagen synthesis of HSC and secretion of TGF-beta,TNF-alpha and IL-1 from Kupffer cells.</p>
Subject(s)
Animals , Male , Rats , Aniline Compounds , Pharmacology , Carbon Tetrachloride , Cell Division , Cells, Cultured , Collagen Type I , Hepatocytes , Cell Biology , Hydroxybutyrates , Pharmacology , Immunosuppressive Agents , Pharmacology , Interleukin-1 , Metabolism , Isoxazoles , Metabolism , Pharmacology , Kupffer Cells , Cell Biology , Rats, Sprague-Dawley , Transforming Growth Factor beta , MetabolismABSTRACT
<p><b>AIM</b>To investigate the effect of inhalation of cyclosporin (CsA) on antigen-induced airway inflammation in Sprague-Dawley rats.</p><p><b>METHODS</b>Rats were sensitized with antigen (ovalbumin, OA). After two weeks, the sensitized rats were pretreated with aerosol CsA (5, 10, 20 g x L(-1)), once per day for 7 days. Then, the sensitized rats were challenged with OA (10 g x L(-1), once per day) for 2 days at day 20 after sensitization. The number of eosinophils in bronchoalveolar lavage fluid (BALF) and peripheral blood, histological changes of lung tissue, and TNF-alpha content in BALF were investigated.</p><p><b>RESULTS</b>Inhalation of CsA significantly reduced the number of eosinophils in BALF and peripheral blood, inflammatory infiltration and tissue edema of lung tissue, decreased the content of TNF-alpha in BALF.</p><p><b>CONCLUSION</b>Inhalation of CsA inhibited airway inflammation in rats, and the mechanism is related to inhibition of TNF-alpha release.</p>
Subject(s)
Animals , Female , Male , Rats , Administration, Inhalation , Asthma , Metabolism , Pathology , Bronchoalveolar Lavage Fluid , Chemistry , Cyclosporine , Pharmacology , Eosinophils , Pathology , Immunosuppressive Agents , Pharmacology , Leukocyte Count , Lung , Pathology , Ovalbumin , Rats, Sprague-Dawley , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To compare the bronchofilating and antiallergic effects with piclamilast with ciclamilast, the second-generation phosphodiesterase 4 (PDE4) selective inhibitors.</p><p><b>METHODS</b>Effects of piclamilast and ciclamilast on airway smooth muscle (ASM) at resting tension, carbachol-induced contraction and the synergistic effect of two agents on isoproterenol-induced bronchorelaxation were evaluated in the isolated tracheal strips of guinea pig in a cumulative manner in vitro. Slow reaction substance of anaphylaxis (SRS-A) release from lung tissues of the sensitized guinea pigs after antigen challenge was examined by bioassay. Antiallergic effect of piclamilast, ciclamilast and rolipram on the isolated ASM of sensitized guinea pigs were evaluated with Schultz-Dale reaction.</p><p><b>RESULTS</b>Piclamilast and ciclamilast showed bronchorelaxant effect in ASM at resting tension. EC50 values of piclamilast and ciclamilast were 1.00 x 10(-5) mol/L and 0.84 x 10(-5) mol/L. Piclamilast and ciclamilast could both enhance the bronchodilating effect of isoproterenol in the isolated ASM of guinea pig, reduce the amount of SRS-A released from lung tissues of the sensitized guinea pigs and also inhibit ovalbumin (OA)-induced bronchoconstruction (Schultz-Dale reaction).</p><p><b>CONCLUSION</b>The results indicate the bronchodilating effect of ciclamilast is as potent as piclamilast, but the antiallergic effect of ciclamilast is significantly more potent than that of piclamilast.</p>
Subject(s)
Animals , Female , Male , Anti-Allergic Agents , Pharmacology , Benzamides , Pharmacology , Bronchodilator Agents , Pharmacology , Dose-Response Relationship, Drug , Guinea Pigs , In Vitro Techniques , Isoproterenol , Pharmacology , Phosphodiesterase Inhibitors , Pharmacology , Pyridines , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To compare the bronchodilating effect of RR-formoterol (RR-FMT) with that of racemic formoterol (rac-FMT) on human bronchus.</p><p><b>METHODS</b>Human bronchial spiral strips (2 - 4 mm internal diameter,15 mm length) were suspended in tissue baths under resting tension of 1.0 g. The changes of tension induced by RR-FMT and rac-FMT(10 pmol x L(-1) - 3.2 micromol x L(-1)) in a cumulative concentration manner were studied under resting tension conditions or precontraction with carbamylcholine (10 micromol x L(-1)) or histamine(100 micromol x L(-1)) in human bronchus.</p><p><b>RESULT</b>The bronchodilating effect of RR-FMT was more potent than that of rac-FMT under resting condition(P<0.05). RR-FMT and rac-FMT reversed histamine or carbamylcholine-induced contraction, and the bronchodilating effect of RR-FMT was more potent than that of rac-FMT (P<0.05).</p><p><b>CONCLUSION</b>The bronchodilating effect of RR-FMT is more potent than that of rac-FMT in both the resting condition and carbamylcholine or histamine-induced contraction in human bronchus in vitro.</p>
Subject(s)
Aged , Humans , Middle Aged , Bronchi , Physiology , Bronchodilator Agents , Pharmacology , Carbachol , Pharmacology , Dose-Response Relationship, Drug , Ethanolamines , Pharmacology , Formoterol Fumarate , Histamine , Pharmacology , In Vitro Techniques , StereoisomerismABSTRACT
<p><b>OBJECTIVE</b>To investigate antigen-induced changes of leukotriene B(4)(LTB(4))content and LTA(4)-hydrolase mRNA expression in lung tissue and cerebral cortex in sensitized rats.</p><p><b>METHODS</b>The contents of LTB(4) in lung tissue and cerebral cortex homogenates and LTA(4)-hydrolase mRNA expression after antigen challenge by aerosol were respectively detected by reverse-phase high performance liquid chromatography(RP-HPLC) and semi-quantitative RT-PCR.</p><p><b>RESULT</b>The LTB(4) levels in lung tissue and cerebral cortex homogenates in asthmatic rats were significantly higher than those in control (P%0.05), and LTA4-hydrolase mRNA expression was also increased in asthmatic group. Dexamethason(DXM, 0.5 mg/kg, i.p.) decreased the LTB(4) content and inhibited the LTA(4)-hydrolase mRNA expression significantly in asthmatic rats(P%0.05).</p><p><b>CONCLUSION</b>LTB(4) content and LTA(4)-hydrolase mRNA expression in cerebral cortex and lung tissue are increased in asthmatic rats, and there may exist neuroimmunological cross-talking between central nervous system and lung tissue in asthma.</p>
Subject(s)
Animals , Female , Male , Rats , Asthma , Metabolism , Cerebral Cortex , Chemistry , Metabolism , Epoxide Hydrolases , Genetics , Leukotriene B4 , Lung , Chemistry , Metabolism , RNA, Messenger , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To study inhibitory the effects of Cryptoporus volvatus ferment substance(CVFS) on leukotriene production in vitro from neutrophils in rats.</p><p><b>METHODS</b>Neutrophil aggregation was induced by intraperitoneal injection of glycogen in rats. After 16 h, intraperitoneal lavage fluid(PLF) was collected and neutrophils were removed. Neutrophils were stimulated by calcium ionophore A23187 in vitro to produce leukotriene B(4), C(4), D(4). The concentrations of leukotriene B(4), C(4) and D(4) were measured by reversed-phase high-performance liquid chromatography(HPLC).</p><p><b>RESULT</b>CVFS at 0.25, 1, 4 mg x L(-1)decreased leukotriene B(4), C(4), D(4) release from neutrophils in a concentration-dependent manner. Inhibitory rate of CVFS 0.25, 1, 4 mg x L(-1 )on A23187-induced leukotriene B(4) production was 27.4%, 54.2% and 78.8%(P<0.05), respectively. Inhibitory rate of leukotriene C(4) production was 65.1%, 74.3 and 79.0%(P<0.05), respectively. Inhibitory rate of leukotriene D(4) production was 55.6%, 60.9% and 72.8%(P<0.05), respectively.</p><p><b>CONCLUSION</b>The results suggest that suppression of leukotriene release may be a mechanism of the anti-inflammation and anti-asthma effects of CVFS.</p>
Subject(s)
Animals , Female , Male , Rats , Anti-Asthmatic Agents , Pharmacology , Dose-Response Relationship, Drug , Fermentation , Leukotriene B4 , Bodily Secretions , Leukotriene C4 , Bodily Secretions , Leukotriene D4 , Bodily Secretions , Neutrophils , Physiology , Polyporaceae , Metabolism , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To study the effects of polysaccharides of cultured Cryptoporus volvatus(CVPS) on airway hyperresponsiveness of ovalbumin-sensitized rats and to evaluate their mechanisms.</p><p><b>METHODS</b>Polysaccharides A, B (5mg/kg, 20mg/kg) and ketotifen(5mg/kg) or vehicle(same volume of saline) were administrated orally for 10 days in ovalbumin -sensitized rats, methacholine bronchial provocation tests were performed to determine airway hyperresponsiveness. Bronchoalveolar lavage fluid (BALF) and peritoneal lavage fluid were prepared after the animals were challenged by nebulized antigen. The differential white cell count in BALF,and the degranulated mast cell count as well as differential white cell count in peritoneal lavage fluid were performed.</p><p><b>RESULT</b>Polysaccharides markedly inhibited the increased lung resistance and the decreased lung compliance induced by antigen challenge,significantly reduced total cell counts and absolute eosinophil counts in BALF(P<0.05); polysaccharides B was more effective than polysaccharides A. They also inhibited recruitment of inflammatory cells in peritoneal lavage fluid and inhibited the allergen-induced mast cell degranulation.</p><p><b>CONCLUSION</b>Polysaccharides of CVPS inhibit airway hyperresponsiveness by stabilizing mast cell membranes and reducing infiltration and chemotaxis of eosinophils and may be developed as a potential anti-asthmatic drug.</p>
Subject(s)
Animals , Male , Rats , Anti-Asthmatic Agents , Pharmacology , Bronchial Hyperreactivity , Drug Therapy , Bronchoalveolar Lavage Fluid , Cell Biology , Cell Degranulation , Mast Cells , Physiology , Ovalbumin , Allergy and Immunology , Polyporaceae , Chemistry , Polysaccharides , Pharmacology , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To establish determination methods of eotaxin mRNA and TNF-alpha mRNA expression in the lung tissue of mice.</p><p><b>METHODS</b>Eotaxin mRNA and TNF-alpha mRNA expressions were determined by semi-quantitative RT-PCR. The functional implications of eotaxin mRNA and TNF-alpha mRNA expression were examined by detecting the numbers of total leucocytes and eosinophils in bronchoalveolar lavage fluid(BALF).</p><p><b>RESULT</b>Eotaxin mRNA and TNF-alpha mRNA expression in lung tissue total numbers of leucocyte and numbers of eosinophil in BALF increased in sensitized mice compared with those in normal mice. Dexamethasone significantly but did not inhibit eotaxin mRNA and TNF-alpha mRNA expressions, and eosinophil infiltration in the lungs of the sensitized mice. A compound preparation of traditional Chinese medicine inhibited eotaxin mRNA and eosinophil infiltration, influenced TNF-alpha mRNA expression.</p><p><b>CONCLUSION</b>Increased eotaxin mRNA expression in lung tissue is associated with eosinophil infiltration in BALF, which indicates that the methods of semi-quantitative RT-PCR may be useful to the study of the mechanism of antiasthmatic medicine.</p>
Subject(s)
Animals , Female , Male , Mice , Anti-Inflammatory Agents , Pharmacology , Asthma , Drug Therapy , Metabolism , Bronchoalveolar Lavage Fluid , Cell Biology , Chemokine CCL11 , Chemokines, CC , Genetics , Dexamethasone , Pharmacology , Disease Models, Animal , Eosinophils , Physiology , Leukocyte Count , Lung , Metabolism , Mice, Inbred ICR , RNA, Messenger , Reverse Transcriptase Polymerase Chain Reaction , Tumor Necrosis Factor-alpha , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To study the effects of very late antigen(VLA) antagonist BIO-1211 on eosinophil chemotaxis, recruitment and mediator release.</p><p><b>METHODS</b>Eosinophil chemotaxis was induced by platelet activating factor(PAF) in vitro and eosinophil recruitment and release were determined in vivo.</p><p><b>RESULT</b>VLA antagonist BIO-1211 inhibited eosinophil chemotaxis induced by PAF. The inhibitory rates at 4x10(-11), 4x10(-10), 4x10(-9) mol x L(-1) were 24.9%, 29.9%, and 31.3%, respectively. Pretreatment by BIO-1211 1, 3 and 10 mg x kg(-1) intraperitoneally inhibited the recruitment of eosinophils in PAF in the rat induced by Sephadex in a dose dependent manner. Inhibitory rates were 60.3%, 68.9%, and 72.9%(P<0.05), respectively. BIO-1211 did not inhibit eosinophil peroxidase(EPO) release from eosinophils.</p><p><b>CONCLUSION</b>BIO-1211 inhibits eosinophil chemotaxis and recruitment, alleviates local inflammation, and may represent a new type of drug for allergic diseases.</p>
Subject(s)
Animals , Male , Rats , Cell Movement , Chemotaxis, Leukocyte , Dose-Response Relationship, Drug , Eosinophil Peroxidase , Eosinophils , Physiology , Integrin alpha4beta1 , Physiology , Oligopeptides , Pharmacology , Peroxidases , Bodily Secretions , Platelet Activating Factor , Pharmacology , Rats, Sprague-DawleyABSTRACT
<p><b>OBJECTIVE</b>To study action of Cryptoporus volvatus ferment substance (CVFS) on leukotriene production of polymorphonuclear leukocytes in rats.</p><p><b>METHODS</b>The level of slow reaction substance (SRS) and leukotriene B4 (LTB4) in polymorphonuclear leukocytes (PMNs) in rats in vitro were determined with bioassay and HPLC.</p><p><b>RESULTS</b>CVFS 0.9, 2.7 g.kg-1 by ig significantly inhibited SRS and LTB4 production in PMNs in rats in vivo.</p><p><b>CONCLUSION</b>The inhibition effect of CVFS on SRS and LTB4 release may be related to its mechanism of anti-inflammation and anti-asthma.</p>
Subject(s)
Animals , Female , Male , Rats , Anti-Asthmatic Agents , Pharmacology , Anti-Inflammatory Agents, Non-Steroidal , Pharmacology , Cell Separation , Dose-Response Relationship, Drug , Drugs, Chinese Herbal , Pharmacology , Guinea Pigs , Leukotriene B4 , Metabolism , Neutrophils , Metabolism , Polyporaceae , Chemistry , Rats, Sprague-Dawley , SRS-A , MetabolismABSTRACT
OBJECTIVE: To assess the change of cGMP-PDE and cAMP-PDE activity in a rat lung model of asthma. METHODS: cGMP-PDE and cAMP-PDE activity were determined by HPLC. RESULTS: Both cAMP-PDE activity and cGMP-PDE activity in the lung tissue of antigen-challenged rats were higher than that from the normal rats (P <0.05). CONCLUSION: In the rat lung model of asthma, cyclic nucleotides phosphodiesterase activity was elevated. This may be significant in the pathogenesis of asthma.