Evaluation of the immunotoxicity of chlorothalonil to striped bass phagocytes following in vitro exposure

✍ Scribed by Cal Baier-Anderson; Robert S. Anderson

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 92 KB
• Volume: 17
• Category: Article
• ISSN: 0730-7268
• DOI: 10.1002/etc.5620170815

✦ Synopsis

The fungicide chlorothalonil (TCIN), with both agricultural and horticultural applications, is a common aquatic pollutant. The immunotoxic potential of TCIN was investigated following a 20-h in vitro exposure of striped bass (Morone saxatilus) macrophages to a range of sublethal concentrations. Cells from the anterior kidney were separated by density-gradient centrifugation to obtain a macrophage-enriched cell population. Following TCIN exposure, reactive oxygen species (ROS) production was evaluated using luminol-augmented chemiluminescence; phagocytic capacity was measured by the ingestion of fluorescein isothiocyanateconjugated yeast; and NADPH production was estimated by monitoring the reduction of a water-soluble tetrazolium, 3-(4,5dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt. Results indicate that TCIN, at concentrations Ն250 g/L, decreased ROS production in both zymosan-and phorbol myristate acetate (PMA)-stimulated cells in a dose-dependent manner. The PMA-stimulated NADPH production coincident with the respiratory burst was also decreased at concentration Ն250 g/L. The TCIN did not appear to alter phagocytic ability. Taken together, these results indicate that the mechanism of toxicity affects the activation or function of the NADPH oxidase but not the uptake of particles by phagocytosis, and that these effects can probably be localized to the signal transduction pathway or the assemblage of NADPH oxidase.