Macrophage solubilization and cytotoxicity of indium-containing particles as in vitro correlates to pulmonary toxicity in vivo.

Macrophage-solubilized indium-containing particles (ICPs) were previously shown in vitro to be cytotoxic. In this study, we compared macrophage solubilization and cytotoxicity of indium phosphide (InP) and indium-tin oxide (ITO) with similar particle diameters (∼ 1.5 µm) and then determined if relative differences in these in vitro parameters correlated with pulmonary toxicity in vivo.

Macrophage solubilization and cytotoxicity of indium-containing particles in vitro.

Indium-containing particles (ICPs) are used extensively in the microelectronics industry. Pulmonary toxicity is observed after inhalation exposure to ICPs; however, the mechanism(s) of pathogenesis is unclear. ICPs are insoluble at physiological pH and are initially engulfed by alveolar macrophages (and likely airway epithelial cells).

Pleural effects of indium phosphide in B6C3F1 mice: nonfibrous particulate induced pleural fibrosis.

The mechanism(s) by which chronic inhalation of indium phosphide (InP) particles causes pleural fibrosis is not known. Few studies of InP pleural toxicity have been conducted because of the challenges in conducting particulate inhalation exposures, and because the pleural lesions developed slowly over the 2-year inhalation study. The authors investigated whether InP (1 mg/kg) administered by a single oropharyngeal aspiration would cause pleural fibrosis in male B6C3F1 mice.

Alveolar macrophage cytotoxicity for normal lung fibroblasts is mediated by nitric oxide release.

Nitric oxide (NO) released by activated alveolar macrophages (AM) can mediate effects on target cells and can also react with superoxide anion (O2-) to form peroxynitrite (PN), a highly cytotoxic product. The role of NO and PN in AM cytotoxicity for normal lung cells was investigated using co-cultures of rat lung fibroblasts (FB) and rat AM treated with lipopolysaccharide + interferon-gamma (LI). AM and FB, alone and in co-culture, were treated with LI for 5 days and cell viability measured.

Comparative pulmonary absorption, distribution, and toxicity of copper gallium diselenide, copper indium diselenide, and cadmium telluride in Sprague-Dawley rats.

Copper gallium diselenide (CGS), copper indium diselenide (CIS), and cadmium telluride (CdTe) are novel compounds used in the photovoltaic and semiconductor industries. This study was conducted to characterize the relative toxicities of these compounds and to evaluate the pulmonary absorption and distribution after intratracheal instillation. Female Sprague-Dawley rats were administered a single equimolar dose (70 mM) of CGS (21 mg/kg), CIS (24 mg/kg), CdTe (17 mg/kg), or saline by intratracheal instillation.