Toxicity of Fenclor 42 on Immunocompetent Cells

Abstract

Polychlorinated biphenyls (PCBs) are environmental contaminants, whose toxicity is related to the degree and the position of chlorine substitutes. Fenclor 42 is a mixture of trichlorobiphenyls employed for industrial use in Italy. In order to evaluate its effects on the immune system, CD2F1 mice were treated with Fenclor 42 at different doses and schedules. Spleen weights, total number of splenocytes and relative spleen weight decreased significatively following a single or a prolonged exposure to different doses of Fenclor 42. An analysis of the functional activity of splenocytes showed that the proliferative response to Con A and PWM mitogens was also inhibited by Fenclor 42. Splenic parameters returned to normal values within 5 days after a single injection and between 8–15 days after a subchronic administration of the compound. The capability of splenocytes to proliferate, following mitogen stimulation, was restored between day 5 and day 8 according to the different schedules of treatment. By comparison, Fenclor 42 never affected NK activity. These data clearly indicate damage at the splenic level by Fenclor 42. Studies are in progress to elucidate the mechanisms involved in the immunotoxic response.