ovalbumin and Respiration-Disorders

Asthma has been the most prevalent chronic respiratory disease (Mensah et al. J Allergy Clin Immunol 142:744-748, 2018). To explore pathogenic mechanism or new treatments of asthma, mice have been utilized to model the disease. Eosinophilic airway inflammation, allergen specific-IgE, and airway hyperresponsiveness have been characteristic features of allergic asthma (Drake et al. Pulm Ther 5:103-115, 2019). In mouse models, airway hyperresponsiveness to inhaled broncho-constrictor agents such as methacholine chloride (MCh) has been a key disease marker (Alessandrini et al. Front Immunol 11:575936, 2020). A variety of systems to assess airway reactivity in mice are currently available. Here, three distinct systems are described as these have been used in many publications. In the first system, an invasive system in which mice are anesthetized and intubated followed by mechanical ventilation, lung resistance (R), dynamic compliance (C), and other respiratory parameters with MCh challenge are measured. In the second system, a noninvasive system equipped with a chamber in which mice can move freely and spontaneously breathe, changes in airways with MCh challenge are measured as enhanced pause (Penh) values. In the third system, in vitro airway smooth muscle (ASM) reactivity is monitored in an extracted mouse tracheal duct with a cholinergic agonist challenge or electrical stimulation. Each of these systems has unique features, benefits, or disadvantages.

Topics: Animals; Asthma; Bronchial Hyperreactivity; Disease Models, Animal; Eosinophilia; Immunoglobulin E; Methacholine Chloride; Mice; Mice, Inbred BALB C; Ovalbumin; Respiration Disorders; Respiratory Hypersensitivity

Epidemiological studies suggest that stress has an impact on asthmatic exacerbations. We evaluated if repeated stress, induced by forced swimming, modulates lung mechanics, distal airway inflammation and extracellular matrix remodeling in guinea pigs with chronic allergic inflammation.. Guinea pigs were submitted to 7 ovalbumin or saline aerosols (1-5 mg/ml during 4 weeks; OVA and SAL groups). Twenty-four hours after the 4th inhalation, guinea pigs were submitted to the stress protocol 5 times a week during 2 weeks (SAL-S and OVA-S groups). Seventy-two hours after the 7th inhalation, guinea pigs were anesthetized and mechanically ventilated. Resistance and elastance of the respiratory system were obtained at baseline and after ovalbumin challenge. Lungs were removed, and inflammatory and extracellular matrix remodeling of distal airways was assessed by morphometry. Adrenals were removed and weighed.. The relative adrenal weight was greater in stressed guinea pigs compared to non-stressed animals (p < 0.001). Repeated stress increased the percent elastance of the respiratory system after antigen challenge and eosinophils and lymphocytes in the OVA-S compared to the OVA group (p < 0.001, p = 0.003 and p < 0.001). Neither collagen nor elastic fiber contents were modified by stress in sensitized animals.. In this animal model, repeated stress amplified bronchoconstriction and inflammatory response in distal airways without interfering with extracellular matrix remodeling.

Topics: Administration, Inhalation; Adrenal Glands; Analysis of Variance; Animals; Disease Models, Animal; Extracellular Matrix; Guinea Pigs; Hypersensitivity; Inflammation; Male; Neutrophil Infiltration; Organ Size; Ovalbumin; Physical Stimulation; Respiration Disorders; Stress, Psychological; Swimming

Epidemiological and experimental studies suggest a positive correlation between chronic respiratory inflammatory disease and the ability to cope with adverse stress. Interactions between neuroendocrine and immune systems are believed to provide insight toward the biological mechanisms of action. The utility of an experimental murine model was employed to investigate the immunological consequences of stress-controllability and ovalbumin-induced airway inflammation. Pre-conditioned uncontrollable stress exacerbated OVA-induced lung histopathological changes that were typical of Th2-predominant inflammatory response along respiratory tissues. Importantly, mice given the ability to exert control over aversive stress attenuated inflammatory responses and reduced lung pathology. This model represents a means of investigating the neuro-immune axis in defining mechanisms of stress and respiratory disease.

Topics: Analysis of Variance; Animals; Antigens, CD; Bronchoalveolar Lavage; Cytokinins; Disease Models, Animal; Female; Flow Cytometry; Inflammation; Lung; Mice; Mice, Inbred BALB C; Ovalbumin; Random Allocation; Respiration Disorders; Stress, Psychological; Th2 Cells; Time Factors; Weight Gain

Current techniques to evaluate the efficacy of potential treatments for airways diseases in small animal models are generally invasive and terminal. In this contribution we illustrate the usefulness of magnetic resonance imaging (MRI) to obtain anatomical and functional information of the lung, with the scope of developing a non-invasive approach for the routine testing of drugs in rat models of airways diseases. With MRI, the disease progression can be followed in the same animal. Thus, a significant reduction in the number of animals used for experimentation is achieved, as well as minimal interference with their well-being and physiological status. In addition, MRI has the potential to shorten the duration of the observation period after disease onset since the technique is able to detect changes before these are reflected in invasively determined parameters of inflammation.

Topics: Allergens; Animals; Bronchoalveolar Lavage Fluid; Magnetic Resonance Imaging; Ovalbumin; Pulmonary Disease, Chronic Obstructive; Rats; Respiration Disorders

We tested the hypothesis that allergen-induced mediator release augments the magnitude of isocapnic dry gas hyperpnea-induced bronchoconstriction in sensitized guinea pigs. Male Hartley guinea pigs were sensitized by spontaneous inhalation of ovalbumin (OA) aerosol on days 0 and 7 of the study. On day 14, sensitized animals again breathed OA aerosol and were prospectively divided into a group that exhibited labored breathing (LB), presumably reflecting OA-induced inflammatory mediator release, and a group that did not exhibit LB at this time. Control guinea pigs breathed saline aerosol on days 0, 7, and 14. Bronchoalveolar lavage on day 17 disclosed relative eosinophilia in OA+LB, but not in OA-LB, animals. On day 17, the bronchoconstrictor responses to increasing intravenous (i.v.) doses of acetylcholine (ACh), substance P (SP), neurokinin A (NKA), and capsaicin, as well as dry gas hyperpnea, were measured in vivo in animals from each group. Control and OA-LB guinea pigs exhibited similar responses, but OA+LB animals demonstrated augmented bronchoconstriction induced by i.v. administration of ACh, SP, or NKA. However, despite their augmented responsiveness to these exogenous constrictor agonists, OA+LB animals displayed no greater bronchoconstriction after dry gas hyperpnea or i.v. capsaicin administration. It is known that both dry gas hyperpnea and i.v. capsaicin cause bronchoconstriction in guinea pigs by releasing endogenous tachykinins from airway sensory C-fibers. Thus, our results suggest that allergen-induced mediator release impairs endogenous tachykinin release from airway sensory C-fibers in guinea pigs.

Topics: Acetylcholine; Airway Resistance; Allergens; Animals; Bronchial Hyperreactivity; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Capsaicin; Carbon Dioxide; Dose-Response Relationship, Drug; Eosinophils; Guinea Pigs; Male; Neurokinin A; Neurotransmitter Agents; Ovalbumin; Respiration Disorders; Substance P; Tidal Volume