title: Partitioning of nasal and pulmonary resistance changes during noninvasive plethysmography in mice.
abstract: Double-chamber plethysmography is a well established noninvasive method of assessing airflow obstruction in small lab animals. It allows measurement of the specific airway resistance (sRaw), which unlike enhanced pause (Penh), is a meaningful airway mechanics parameter. Since sRaw is measured in spontaneously breathing mice, a limitation of the method is the inability to exclude nasal resistance changes. We recently showed that mice are not truly obligate nasal breathers and that after nasal occlusion, nasally breathing mice can transition to an oral mode of breathing. We now show that it is experimentally possible to algebraically separate the average nasal and pulmonary (including laryngeal) components of total airway resistance change by a series of measurements made across groups of mice breathing nasally or orally, assuming that oral resistance remains constant. Using this approach, we show that nasal resistance change comprises one-half or more of the total resistance change during methacholine challenge. Inhibition of mucin secretion from airway goblet cells attenuates pulmonary but not nasal airway hyperresponsiveness (AHR), and nasal AHR in a murine model of rhinitis may be related to edema.
authors.affiliation: Institute of Genomics and Integrative Biology, Mall Road, Delhi, India 110 007. a.agrawal@igib.res.in
authors.forename: Anurag
authors.initials: A
authors.lastname: Agrawal
authors.forename: Shashi Kant
authors.initials: SK
authors.lastname: Singh
authors.forename: Vijay Pal
authors.initials: VP
authors.lastname: Singh
authors.forename: Edward
authors.initials: E
authors.lastname: Murphy
authors.forename: Indu
authors.initials: I
authors.lastname: Parikh
mesh_terms: D000402:Airway Obstruction / Q000503:physiopathology; D000403:Airway Resistance / Q000502:physiology*; D000818:Animals; D001249:Asthma / Q000503:physiopathology; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008168:Lung / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009077:Mucins / Q000378:metabolism; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D009296:Nasal Cavity / Q000502:physiology*; D010991:Plethysmography; D011654:Pulmonary Edema / Q000473:pathology / Q000503:physiopathology; D015656:Respiratory Mechanics; D006255:Rhinitis, Allergic, Seasonal / Q000503:physiopathology
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009077:Mucins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate