Intravenous injection of hypertonic NaCl solution stimulates pulmonary C-fibers in dogs
| Autor: | T. E. Pisarri, Hazel M. Coleridge, J. C. G. Coleridge, A. Jonzon |
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| Rok vydání: | 1991 |
| Předmět: |
medicine.medical_specialty
Physiology Bronchi Receptors Cell Surface Stimulation Cardiovascular System Dogs Nerve Fibers Physiology (medical) Internal medicine medicine.artery Animals Urea Medicine Respiratory system Lung Saline Solution Hypertonic biology business.industry Respiration Osmolar Concentration Fissipedia biology.organism_classification Adaptation Physiological Solutions Glucose Endocrinology medicine.anatomical_structure Anesthesia Injections Intravenous Reflex bradycardia Pulmonary artery Reflex Tonicity Cardiology and Cardiovascular Medicine business Mechanoreceptors |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 260:H1522-H1530 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.1991.260.5.h1522 |
| Popis: | Intravenous injection of hypertonic NaCl solution evokes reflex bradycardia and hypotension, effects thought to result from stimulation of afferent vagal endings in the lungs. To identify the afferents responsible for these effects, we recorded vagal impulses arising from endings in the lungs and lower airways of anesthetized dogs and examined the response to injection of hypertonic solutions into the pulmonary circulation. Injection of 4,800 mmol/l NaCl solution (1 ml/kg) stimulated 39 of 49 pulmonary C-fibers, their impulse frequency increasing 35-fold. Stimulation was concentration dependent, the minimum effective concentration being between 1,200 and 4,800 mmol/l. Rapidly adapting receptors were also stimulated in a concentration-dependent manner, 35 of 41 receptors being stimulated by 4,800 mmol/l NaCl solution, firing increasing fivefold. Bronchial C-fibers were not stimulated by injection into the pulmonary circulation but were by injection into the bronchial artery. Hypertonic urea solutions had qualitatively similar but smaller effects on pulmonary C-fibers and rapidly adapting receptors. The results suggest that the reflex effects of intravenous injection of hypertonic solutions result principally from stimulation of pulmonary C-fibers. |
| Databáze: | OpenAIRE |
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