Respiratory epithelial permeability after cigarette smoke exposure in guinea pigs.
The purpose of this study was to determine the pathology of cigarette smoke-increased permeability at the bronchioalveolar junction of the guinea pig. After exposure to either smoke or room air, guinea pigs were anesthetized and fluorescein isothiocyanate-dextran (FITC-D, mol wt 10,000) was aerosolized into their lungs. Blood samples taken through a carotid arterial cannula were analyzed by gel chromatography and spectrofluorometry for the presence of FITC-D. The results confirmed that, after smoke exposure, increased amounts of intact FITC-D molecules with a reported Einstein-Stokes radius of 22.2 A crossed the respiratory epithelium into the vascular space. Transmission electron-microscopic studies showed that the FITC-D diffused across damaged type I pneumocyte membranes and cytoplasm to reach the basal lamina and entered the alveolar capillaries through endothelial tight junctions. Damage to the alveolar epithelium was more frequent for the smoke-exposed animals than the room air-exposed animals (P less than 0.05). We conclude that smoke exposure damages type I cells and that inhaled FITC-D crosses the epithelial barrier at damaged type I cells of the bronchioloalveolar junctions.
Burns
A R
AR
Department of Pathology, University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, Canada.
Hosford
S P
SP
Dunn
L A
LA
Walker
D C
DC
Hogg
J C
JC
D000336:Aerosols; D000818:Animals; D001980:Bronchi / Q000648:ultrastructure; D002462:Cell Membrane / Q000648:ultrastructure; D002463:Cell Membrane Permeability; D003911:Dextrans; D004848:Epithelium / Q000648:ultrastructure; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives*; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006168:Guinea Pigs; D008168:Lung / Q000648:ultrastructure*; D008297:Male; D011650:Pulmonary Alveoli / Q000648:ultrastructure; D012016:Reference Values; D014028:Tobacco Smoke Pollution
D000336:Aerosols; D003911:Dextrans; D005452:Fluoresceins; D005456:Fluorescent Dyes; D014028:Tobacco Smoke Pollution; C015219:fluorescein isothiocyanate dextran; D016650:Fluorescein-5-isothiocyanate