Effects of changes in osmolarity on isolated human airways
| Autor: | R. C. Raatgeep, I. L. Bonta, R. C. Jongejan, K. F. Kerrebijn, J. C. de Jongste |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Adult
Male medicine.medical_specialty Physiology Hypertonic Solutions chemistry.chemical_element Bronchi Constriction Pathologic Calcium Tachyphylaxis chemistry.chemical_compound Physiology (medical) Internal medicine medicine Respiratory muscle Humans Methacholine Compounds Urea Mannitol Methacholine Chloride Aged Aged 80 and over Saline Solution Hypertonic Osmotic concentration Leukotriene C4 Osmolar Concentration Isoproterenol Muscle Smooth Middle Aged Hypertonic saline Endocrinology Hypotonic Solutions chemistry Anesthesia Tonicity Female Bronchoconstriction medicine.symptom Muscle Contraction |
| Zdroj: | Journal of Applied Physiology. 68:1568-1575 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1990.68.4.1568 |
| Popis: | The effects of hypo- and hyperosmolarity on the function of isolated human airways were studied. Changes in osmolarity induced an increasing bronchoconstriction that was proportional to the magnitude of the change in osmolarity. Hypertonicity-induced airway narrowing resulted when buffer was made hypertonic with sodium chloride or mannitol but not with urea. The airways showed no tachyphylaxis to repetitive exposure to hypo- and hypertonic buffer of 200 and 600 mosM, respectively. The bronchoconstriction was not secondary to stimulation of H1 or leukotriene C4/D4 receptors or the release of prostaglandins in the preparation. The bronchoconstriction in hypotonic buffer was totally dependent on extracellular calcium, whereas in hypertonic buffer the bronchoconstriction seemed partially dependent on intracellular calcium release. Isoprenaline prevented the bronchoconstriction in hyper- or hypotonic buffer of 450 and 250 mosM but not in buffer of 600 and 150 mosM. It is concluded that hypo- and hypertonic buffers lead to bronchoconstriction via different mechanisms, which relate to influx of extracellular calcium in hyposmolar buffer and probably to release of calcium from intracellular stores in hypertonic buffer. In strongly hypertonic buffer, part of the bronchoconstriction may be due to osmotic shrinkage. The relevance of our data for the mechanism of bronchoconstriction after inhalation of hypo- or hypertonic saline depends on whether changes in osmolarity around the airway smooth muscle occur in asthmatics but not in normal subjects, and this has not yet been established. |
| Databáze: | OpenAIRE |
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