Pulmonary effects of prolonged ozone insult in rats. Morphometric evaluation of the central acinus

Journal Article · Fri Aug 01 04:00:00 EDT 1980 · Lab. Invest.; (United States)

OSTI ID:5704806

Boorman, G A; Schwartz, L W; Dungworth, D L

Groups of Sprague-Dawley rats were exposed to 0.2, 0.5, or 0.8 ppM of ozone 8 hours a day for 20, 50, or 90 consecutive days to evaluate the prolonged effect of oxidant exposure on the centriacinar area of the lung. Morphologic evaluation revealed that epithelial changes and accumulations of macrophages in centriacinar regions at 90 days were similar to but less severe than lesions seen at 7 days. Quantification of inflammatory cells in centriacinar regions using scanning electron microscopy revealed a 5-fold increase above controls after exposure to 0.8 ppM of ozone for 20 days. Both the 0.5 and 0.8 ppM exposure groups had significantly (p < 0.05) increased numbers of inflammatory cells within proximal alveoli at all time periods. Morphometric analysis applied to transmission electron microscope micrographs demonstrated that the arithmetic mean thickness of the air-blood barrier was 1.20 /+- 0.13 micrometer. (mean /+ standard deviation) in controls; 2.92 /+- 0.92 micrometer. and 2.17 /+ 0.18 micrometer. in rats exposed to 0.8 ppM of ozone for 20 or 90 days, respectively. The increased thickness was accompanied by an increase in the relative volume of the interstitium. These results indicate that centriacinar lesions induced by ozone diminish with continued exposure, but that significant morphologic alterations do persist through 90 days of exposure at the 0.5 and 0.8 ppM levels but not at the 0.2 ppM ozone level.

• Research Organization: Univ. of California, Davis
• OSTI ID: 5704806
• Journal Information: Lab. Invest.; (United States), Journal Name: Lab. Invest.; (United States) Vol. 43:2; ISSN LAINA
• Country of Publication: United States
• Language: English

Related Subjects

560305* -- Chemicals Metabolism &amp; Toxicology-- Vertebrates-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
BIOLOGICAL EFFECTS
BODY
CHRONIC EXPOSURE
LUNGS
MAMMALS
ORGANS
OZONE
PATHOLOGICAL CHANGES
RATS
RESPIRATORY SYSTEM
RODENTS
TOXICITY
TRACE AMOUNTS
VERTEBRATES