ARSENIC COPPER INTERACTION IN THE KIDNEY OF THE RAT - INFLUENCE OF ARSENIC METABOLITES

The present study was an attempt to investigate whether the renal accu mulation of Cu observed in the kidneys of rats and guinea-pigs exposed to arsenite (As-III) was an effect of arsenite alone or also shared b y its metabolites arsenate (As-V), dimethylarsinic acid and monomethyl arsonic acid. The four arsenic compounds were administered subcutaneou sly and separately to rats for 12 days in increasing doses. Kidney, li ver and blood were taken and analysed for As, Cu and other trace eleme nts by atomic emission spectrometry. Results indicate that administrat ion of As-V leads to renal Cu accumulation similar to that observed on administration of As-III and that the accumulation in both cases is d ependent on the dose of arsenic, although higher doses of As-V were re quired to achieve renal Cu levels comparable to that of As-III. A cons tant molar As:Cu ratio independent of arsenic dose was obtained in the kidney. Dimethylarsinic acid did not affect renal Cu levels at all. A dministration of monomethylarsonic acid led to a slight increase in re nal Cu levels which did not increase further in spite of increased dos es of monomethylarsonic acid. It is concluded from these studies that neither the metabolic transformation of inorganic arsenic to its methy lated products nor its metabolites (dimethylarsinic acid and monomethy larsonic acid) caused the observed renal Cu accumulation, rather, the inorganic form of As, either in the trivalent or pentavalent form is r esponsible.