EFFECTS OF TECHNICAL PCB PREPARATIONS AND FRACTIONS THEREOF ON VITAMIN-A LEVELS IN THE MINK (MUSTELA-VISON)

A variety of biochemical and toxic effects are caused by polychlorinated biphenyls (PCBs) and toxicity varies considerably between animal species. No explanation is available for this variation and the precise mechanism of PCB action is unknown. Altered metabolism of vitamin A has been suggested to be involved in the toxicity of coplanar PCBs and related dioxin-like compounds. The results presented here are part of an extensive study aimed at assessing the effects of PCB congeners, differing in numbers of chlorines in the ortho-positions, on the reproduction in mink (Mustela vison). This paper reports the effects of two technical PCB preparations (Clophen A50 and Aroclor 1254), fractions thereof and a synthetic mixture of coplanar PCBs, on the hepatic, renal, and pulmonary vitamin A content in adult mink. The non- and 1-ortho-CBs in Clophen A50 reduced hepatic and pulmonary vitamin A concentrations in adult mink. Effects of the synthetic mixture of non-ortho-CBs were similar to those of the fraction from Clophen A50 containing non-ortho-CBs. Thus, the three coplanar congeners in the synthetic mixture, together with certain 1-ortho-CBs appeared to be largely responsible for the effects of Clophen A50 observed in this study. Data presented in this study also show that, similar to more commonly used experimental animals, the mink respond to PCB exposure with reduced tissue vitamin A content