Journal of Applied Physiology, Vol 55, Issue 3 770-776, Copyright © 1983 by American Physiological Society
Responses of the lung periphery to 1.0 ppm ozone
A. Gertner, B. Bromberger-Barnea, A. M. Dannenberg Jr, R. Traystman and H. Menkes
We studied responses of the lung periphery to short-term exposures of 1.0
ppm ozone (O3). A fiber-optic bronchoscope was wedged in a segmental airway
of anesthetized male mongrel dogs and was used to deliver O3 to a small
portion of lung. Measurements of resistance through the collateral system
(Rcs) were used to monitor responses to O3. During a 30-min exposure to O3,
Rcs increased within 2 min (early phase) and then continued to increase
throughout the exposure. Bilateral cervical vagotomy or pretreatment with
atropine prevented or reduced the response measured at 2 min but not the
later increase in Rcs. The later increase was reduced with
chlorpheniramine. The administration of indomethacin intravenously and as
an aerosol did not alter the response. These results indicate that the
early phase of the response to 1.0 ppm ozone in the lung periphery is
mediated through the parasympathetic system, and the later phase of the
response is related in part to histamine release. We found no evidence that
metabolites of the cyclooxygenase pathway played a role in these responses.
Furthermore, unlike responses to 0.1 ppm, responses to 1.0 ppm O3 are not
characterized by the development of adaptation or tolerance.
