Effect of ozone and histamine on airway permeability to horseradish peroxidase in guinea pigs.
Airway permeability was studied in groups of male guinea pigs at 2, 8, and 24 h after a 1-h exposure to 1 ppm ozone or at 2 h after a 1-h exposure to filtered air (control). Intratracheal administration of 2 mg horseradish peroxidase (HRP) was followed by blood sampling at 5-min intervals up to 30 min. The rate of appearance of HRP in plasma was significantly higher at 2 and 8 h after ozone exposure than that found in animals examined 2 h after air exposure or 24 h after ozone exposure. A dose of 0.12 mg/kg of subcutaneous histamine given after the 15 min blood sample significantly increased the already elevated permeability seen at 2 h post ozone, but had no effect on animals exposed to filtered air 2 h earlier or to ozone 24 h earlier. No difference was seen in the amount of subcutaneous radiolabeled histamine in the lungs of animals exposed 2 h earlier either to air or to ozone. These data indicate that a short-term exposure to ozone produced a reversible increase in respiratory epithelial permeability to HRP in guinea pigs. The potentiation of this increased permeability by histamine may be another manifestation of ozone-induced hyperreactivity.
Miller
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Gordon
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Warnick
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Amdur
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D000818:Animals; D004848:Epithelium / Q000187:drug effects / Q000502:physiology; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D006735:Horseradish Peroxidase / Q000097:blood / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D010126:Ozone / Q000494:pharmacology*; D010539:Permeability; D010544:Peroxidases / Q000378:metabolism*; D014132:Trachea / Q000187:drug effects / Q000502:physiology*
D010126:Ozone; D006632:Histamine; D006735:Horseradish Peroxidase; D010544:Peroxidases