Influence of age, sex and body condition on zinc, copper, cadmium and metallothioneins in common guillemots (Uria aalge) stranded at the Belgian coast

The common guillemots, Uria aalge, found stranded at the Belgian coast, dis play high levels of Cu in both liver and kidneys. The condition index of th e animals.. defined as the ratio of liver to kidneys mass (Wenzel & Adelung , 1996, The suitability of oiled Guillemots (Uria aalge) as monitoring orga nisms for geographical comparisons of trace element contaminants. Archives of Environmental Contamination and Toxicology, 31, 368-377), influences bot h the metal concentration and its binding to metallothioneins (MT): the low er the condition index, the more emaciated the animals, and the higher the total Cu concentration and the concentration of Cu bound to MT. In less rob ust individuals, our results suggest that Cu could displace Zn from MT, ren dering the Zn ions available to induce a new MT synthesis. Sex-related effe cts also emerged as significantly higher hepatic MT as well as Cu- and Zn-M T concentrations were found in emaciated male guillemots compared to female s. In both organs, Cd concentrations remained low and typically demonstrate d an age-dependent renal accumulation, with no noticeable effect of the con dition index. As a whole, these results suggest that, for guillemots found stranded at the Belgian coast, Cu binding to hepatic and renal MT could fun ction as a protective mechanism, rendering the metal ions unavailable to ex ert any cytotoxic activity. (C) 2001 Elsevier Science Ltd. All rights reser ved.