Distribution of injury and microdosimetry of ozone in the ventilatory unit of the rat

Kent E Pinkerton, R. R. Mercer, Charles Plopper, J. D. Crapo

Research output: Contribution to journalArticle

31 Scopus citations

Abstract

The distribution of ozone-induced injury across ventilatory units of the lungs was determined and compared with the predicted distribution of ozone dose across the same units to evaluate dose-response relationships. Sprague- Dawley rats were exposed to either 0.98 ppm ozone 8 h/day for 90 days or to filtered air only. En bloc microdissection was used to identify and isolate in longitudinal profile the bronchiole-alveolar duct junction, first pair of alveolar duct generations, and intervening bifurcation ridge. The first alveolar outpocketing along the bronchiolar wall of each isolation was used to identify the center of a series of concentric arcs radiating outward at 100-μm intervals across each ventilatory unit. The intercept lengths of each arc with the tissue of alveolar septal tips (edges) and alveolar walls were measured and expressed as a function of distance into the ventilatory unit. Relative ozone dose across the ventilatory unit was estimated using the geometry of the tracheobronchial tree and the volume and surface area distribution within individual ventilatory units. This mathematical model of ozone dose demonstrated a high degree of correlation to the measured tissue injury response. The findings of this study demonstrate that microdosimetry and microtoxicology can be used to determine dose-response relationships within the ventilatory unit and to assess questions of tissue sensitivity in ozone-induced lung injury.

Original languageEnglish (US)
Pages (from-to)817-824
Number of pages8
JournalJournal of Applied Physiology
Volume73
Issue number3
StatePublished - 1992

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Keywords

  • bronchiole-alveolar duct junction
  • dose response
  • en bloc microdissection
  • lung

ASJC Scopus subject areas

  • Endocrinology
  • Physiology
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

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