Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Mechanical consequences of airway smooth muscle relaxation.

Authors
Bouhuys-A; Woestijne-KP
Source
J Appl Physiol 1971 May; 30(5):670-676
NIOSHTIC No.
00186806
Abstract
The nature of airway smooth muscle relaxation was studied in humans. The study group consisted of 22 healthy volunteers, 21 males, 9 to 42 years old. They inhaled an aerosol of isoproterenol (7683592) and phenylephrine (59427) from a pocket nebulizer. Lung volume and airway conductance were measured immediately before and after bronchodilator challenge. Maximum expiratory flow volume, isovolume pressure flow (IVPF), and static lung recoil curves were recorded at these times. Bronchodilation induced a 34.7 percent increase in airway conductance at 50 percent vital capacity (VC), a 33.9 percent increase in the airway conductance/thoracic gas volume ratio, a 9.0 percent increase in maximum expiratory flow at 50 percent VC, and a 3.6 increase in 1 second forced vital expiratory volume. Maximum flows as determined from IVPF curves decreased in two subjects. Bronchodilation did not significantly affect total lung capacity, VC, peak expiratory flow, or static lung recoil pressure. The authors conclude that the observed responses can be explained by the fact that isoproterenol stimulates beta adrenergic receptors, leading to a relaxation of airway smooth muscle. Normal airway smooth muscular tone may allow the large airways to withstand compression forces during forced expiration, thereby allowing dynamic compression to extend further upstream than would be the case if the muscles were less rigid. The significance of the increased compressibility of large airways as a clinical side effect of bronchodilator therapy is not known.
Keywords
NIOSH-Publication; NIOSH-Grant; Pulmonary-system-disorders; Inhalation-studies; Physiological-response; Muscle-function; Pulmonary-function-tests; Laboratory-testing; Drugs
Contact
John B Pierce Fdn Lab John B Pierce Fdn Lab 290 Congress Avenue New Haven, Conn 06519
CODEN
JAPHEV
CAS No.
7683-59-2; 59-42-7
Publication Date
19710501
Document Type
Journal Article
Funding Amount
513539.00
Funding Type
Grant
Fiscal Year
1971
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-R01-OH-00304
Issue of Publication
5
ISSN
8750-7587
Priority Area
Pulmonary-system-disorders
Source Name
Journal of Applied Physiology
State
CT
Performing Organization
John B Pierce Fdn of Conn Inc, New Haven, Connecticut
TOP