The relationship between alveolar epithelial proliferation and airway obstruction after ozone exposure.
BACKGROUND
Proliferating cell nuclear antigen (PCNA) is a component of multiprotein complexes that are expressed during cell proliferation. Ozone induces cell necrosis and a consequent increase in cell proliferation.


METHODS
To investigate the effects of acute ozone inhalation on cell proliferation and airway obstruction in BALB/C mice, we examined enhanced pause (Penh) as an index of airway obstruction and PCNA expression by immunohistochemical staining.


RESULTS
Compared with controls that received filtered air, the ozone-exposed groups had increased PCNA expression in the alveolar epithelial cells. In rank order, the highest PCNA index was found following 2.0 p.p.m. ozone exposure. In the 2.0 p.p.m. ozone group, there was a PCNA index of 16.83 +/- 0.57% (mean +/- SEM; P< 0.01), compared with 4.25 +/- 0.5% at 0.12 p.p.m., 6.83 +/- 0.60 at 0.5 p.p.m and 12.16 +/- 0.48% at 1 p.p.m. Following ozone exposure, Penh was increased in a dose-dependent manner. There was a significant correlation between the PCNA index in alveoli and Penh (r = 0.63, P< 0.01).


CONCLUSIONS
These data suggest that ozone can induce alveolar epithelial cell proliferation in a dose-dependent manner, and that alveolar epithelial cell proliferation is correlated with airway obstruction.
Department of Internal Medicine, Cheju National University College of Medicine, Jesu-si, Jeju-do, Republic of Korea.
A-S
AS
Jang
I-S
IS
Choi
Y-I
YI
Koh
C-S
CS
Park
J-S
JS
Lee
D000280:Administration, Inhalation; D000402:Airway Obstruction / Q000139:chemically induced* / Q000503:physiopathology; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002455:Cell Division / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D010126:Ozone / Q000008:administration & dosage / Q000009:adverse effects*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000378:metabolism / Q000473:pathology*
D018809:Proliferating Cell Nuclear Antigen; D010126:Ozone