title: Quantitative recovery of pulmonary intravascular macrophages from sheep lungs.
abstract: Pulmonary intravascular macrophages (PIMs) adhere to the endothelium of lung capillaries and sequester circulating particles and pathogens from the blood. Iron oxide (gamma Fe2O3) 5 mg/kg, administered intravenously, specifically labeled PIMs in situ within the living sheep. Attempts to isolate gamma Fe2O3-labeled PIMs using vascular perfusion (VP) procedures yielded few cells. To improve recovery of PIMs, a proteolytic lung digestion (PLD) procedure was developed. Following PLD, gamma Fe2O3-containing PIMs were recovered by magnets and the amount of gamma Fe2O3 present measured by fluxgate magnetometry. Proteolytic lung digestion recovered 34% of the total gamma Fe2O3 in lung samples and yielded 2 x 10(5) PIMs/g lung with 95% viability. In contrast, VP recovered only 3% of the total gamma Fe2O3 in the lung; furthermore, less than 2% of the recovered gamma Fe2O3 was cell associated. Proteolytic lung digestion followed by magnetic separation is an effective way to recover viable sheep PIMs for in vitro study.
authors.affiliation: Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02115.
authors.forename: R A
authors.initials: RA
authors.lastname: Rogers
authors.forename: D R
authors.initials: DR
authors.lastname: Tasat
authors.forename: A E
authors.initials: AE
authors.lastname: Warner
authors.forename: J D
authors.initials: JD
authors.lastname: Brain
mesh_terms: D000818:Animals; D002469:Cell Separation / Q000379:methods; D002470:Cell Survival; D002478:Cells, Cultured; D017364:Collagenases / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism; D008168:Lung / Q000098:blood supply / Q000166:cytology*; D016676:Macrophages, Alveolar / Q000166:cytology* / Q000378:metabolism; D008280:Magnetics; D010477:Perfusion; D012756:Sheep
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D017364:Collagenases