title: Ozone-induced accelerated lung clearance of 99mTc-DTPA aerosol in conscious sheep.
abstract: This study was initiated to determine the rate and characteristics of 99mTc-DTPA clearance from the lungs of unanesthetized sheep exposed to varying concentrations of O3 for 4 h in a whole-body exposure chamber. Four sheep exposed to 1 ppm O3 had a monoexponential T50 of 274 +/- 81 min (SD), not significantly different from sham exposures (316 +/- 150); 5 sheep exposed to 2 ppm had a T50 of 234 +/- 101 min, not significantly different from sham exposures (364 +/- 131 min). Five additional unanesthetized sheep exposed to 2 ppm for 4 h via a nasotracheal tube had a T50 of 192 +/- 55 min, significantly different from sham exposures (300 +/- 96 min). The results show that the effect of oxidant pollutants on the permeability of alveolobronchiolar epithelium may be assessed in conscious sheep.
authors.affiliation: Department of Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: W J
authors.initials: WJ
authors.lastname: Hornof
authors.forename: E
authors.initials: E
authors.lastname: Schelegle
authors.forename: M
authors.initials: M
authors.lastname: Kammerman
authors.forename: R A
authors.initials: RA
authors.lastname: Gunther
authors.forename: P E
authors.initials: PE
authors.lastname: Fisher
authors.forename: C E
authors.initials: CE
authors.lastname: Cross
mesh_terms: D000336:Aerosols; D000409:Alanine / Q000031:analogs & derivatives*; D000818:Animals; D008168:Lung / Q000187:drug effects* / Q000378:metabolism; D009942:Organometallic Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics*; D015609:Organotechnetium Compounds; D010126:Ozone / Q000494:pharmacology*; D012756:Sheep / Q000502:physiology*; D015091:beta-Alanine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics
chemical_list: D000336:Aerosols; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; C054752:technetium TC 99m 2,3-diaminopropionic acid; D015091:beta-Alanine; D010126:Ozone; D000409:Alanine