Partitioning of airway responses to inhaled methacholine in the rat
| Autor: | Jason H. T. Bates, C. G. Wang, James G. Martin, R. D. Guttmann, G. U. Dimaria |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Male
medicine.medical_specialty Physiology Airway resistance Esophagus Physiology (medical) Internal medicine medicine Pressure Animals Methacholine Compounds Respiratory system Lung Methacholine Chloride Aerosols Inhalation Chemistry Airway Resistance Respiration Rats Inbred Strains respiratory system Rats Endocrinology Breathing Methacholine Airway medicine.drug |
| Zdroj: | Journal of applied physiology (Bethesda, Md. : 1985). 62(3) |
| ISSN: | 8750-7587 |
| Popis: | We measured the changes in upper and lower airway resistance after inhalation of aerosols of methacholine (MCh) in doubling concentrations (16, 32, 64, and 128 mg/ml) in 11 anesthetized nonintubated spontaneously breathing rats. Upper airway resistance (Ru) increased from a control value of 0.48 +/- 0.04 cmH2O X ml-1 X s (mean +/- SE) to 0.85 +/- 0.15 after 128 mg/ml MCh, whereas lower airway resistance (Rlo) increased from 0.11 +/- 0.03 to 0.21 +/- 0.04. However, there was no correlation between the magnitudes of the changes in Ru and Rlo. In a further seven anesthetized spontaneously breathing rats aerosols of MCh were delivered into the lower airways via a tracheostomy and resulted in increases in Rlo from a control value of 0.20 +/- 0.03 to 0.66 +/- 0.12 after 128 mg/ml MCh. Ru also increased to approximately double its control value. We conclude that inhaled MCh causes narrowing of both Ru and Rlo in the anesthetized rat, the changes in Ru and Rlo are not correlated, and changes in Ru can occur when MCh deposition occurs only in the lower airways. |
| Databáze: | OpenAIRE |
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