Quantitative analysis of particle translocation within the lung.
Fering-J; Soderholm-S; Oberdorster-G
Am Rev Respir Dis 1992 Apr; 145(4)(Pt 2)(Meeting Abstracts):A801
We have shown that ultrafine particles (diameter -20 nm) elicit an acute inflammatory response, among others, after being deposited in the alveoli. The inflammatory response seems to be a sequelae of the interstitialization process which is substantially increased in the case of the ultrafine particles compared to particles of larger size(1). The translocation of deposited particles from the alveoli into the pulmonary tissue per se is of interest in particle-lung interaction studies. We have now developed two approaches for quantitative determination of particles in various rat lung compartments during and as a result of translocation. One is based on an extensive lavage of the excised lung, followed by chemical analysis of particle content in the lavaged lung and extra-pulmonary lymph nodes, and of the lavaged cells and fluid. The latter is assumed to be indicative of particles localized in the alveoli, the former of translocated particles. The second approach is based on magnetometry. Using an array of eight flux-gate magnetometers the particle lung burden of magnetite particles is analyzed in vivo. This noninvasive measurement is independent of the location of the magnetic material within the lung, a significant improvement over previous magnetometric systems. After magnetization of the particles by an external magnetic field, the magnetic signal and its relaxation over 15 min. are recorded. This measurement makes it possible to assess the particle lung burden over long periods of time. The use of signal relaxation has the potential to distinguish between intra- and extracellular material in vivo. The present interpretation of the results indicate that after instillation or inhalation of -1 mg of magnetite, the clearance halftime of "relaxing" material is 40-80 days, as expected from other studies. These results seem to be consistent with approaches using chemistry for quantitative analysis. The magnetometric method is less sensitive than chemical analysis and is limited to particles with magnetic properties like magnetite, but it has the potential for repeated noninvasive measurements of distinct particle populations in the same animal.
Quantitative-analysis; Pulmonary-system-disorders; Respiratory-system-disorders; Lung-function; Laboratory-animals; Animal-studies; Animals; Lung-burden; In-vivo-studies; Nanotechnology
Pulmonary System Disorders
American Review of Respiratory Disease
University of Rochester, Rochester, New York