Liver retinoid concentrations in natural populations of herring gulls (Larus argentatus) contaminated by 2,3,7,8-tetrachlorodibenzo-p-dioxin and in ring doves (Streptopelia risoria) injected with a dioxin analogue

Liver vitamin A was analysed by reverse phase high pressure liquid chromatography in a limited number of herring gull samples collected from New Brunswick coastal and Great Lakes colonies. Both retinol and retinyl palmitate concentrations were significantly different between the New Brunswick and Great Lakes colonies as well as among the Great Lakes colonies. The highest mean values were 864 and 1737 μg/g retinol and retinyl palmitate, respectively, occurring in the New Brunswick gulls. The lowest mean values were 131 and 231 μg/g retinol and retinyl palmitate, respectively, which were detected in Lake Ontario gulls. Retinoid levels were inversely related to the extent of dioxin contamination reported previously. Ring doves received single low-level doses of the dioxin analogue 3,4,3′,4′-tetrachlorobiphenyl and were sacrificed at various times postinjection. Liver retinol decreased significantly as aryl hydrocarbon hydroxylase activity increased. The decrease in retinol concentration was not related to UDP-glucuronyltransferase activity. Retinyl palmitate was unaffected by the analogue under the conditions of this study. These results support the hypothesis that, in wildlife species, hepatic retinoid metabolism is affected by chlorinated dibenzodioxins or other contaminants capable of inducing aryl hydrocarbon hydroxylase.