Distribution Pattern of Inhaled Ultrafine Gold Particles in the Rat Lung

The role of alveolar macrophages in the fate of ultrafine particles in the lung was investigated. Male Wistar-Kyoto rats were exposed to ultrafine gold particles, generated by a spark generator, for 6 h at a concentration of 88 μg/m3 (4 × 106/cm3, 16 nm modal mobility diameter). Up to 7 days, the animals were serially sacrificed, and lavaged cells and lung tissues were examined by transmission electron microscopy. The gold concentration/content in the lung, lavage fluid, and blood was estimated by inductively coupled plasma–mass spectrometry. Gold particles used were spherical and electron dense with diameters of 5–8 nm. The particles were individual or slightly agglomerated. By inductively coupled plasma–mass spectrometry analysis of the lung, 1945 ± 57 ng (mean ± SD) and 1512 ± 184 ng of gold were detected on day 0 and on day 7, respectively, indicating that a large portion of the deposited gold particles was retained in the lung tissue. In the lavage fluid, 573 ± 67 ng and 96 ± 29 ng were found on day ...