A NEW EXPERIMENTAL SYSTEM OF USING FERTILE CHICK EGGS TO EVALUATE VANADIUM ABSORPTION AND ANTIDOTAL EFFECTIVENESS TO PREVENT VANADIUM UPTAKE

To establish the absorption of vanadium compounds such as vanadium chl oride, vanadyl sulfate, and sodium metavanadate and to find effective chelating and reducing agents to cope with the absorption and uptake o f vanadium compounds by embryonic chicks, aqueous vanadium solutions w ith or without chelating and reducing agent solutions were introduced into the air sacs of 14-day-old fertile chick eggs. After incubation o f a further 5 days, mortality, embryonic weight, and vanadium content in the legs and toes were measured. Vanadium concentration in the legs and toes increased linearly as the administration of vanadium compoun ds increased and can be used as an index for vanadium absorption. Vana dium accumulation in the legs and toes, embryonic growth, and mortalit y showed no essential differences among VCl3, VOSO4, and NaVO3. Among 19 antidotal substances tested, deferoxamine mesylate was the most eff ective, and Xylenol Orange, EDTA, and basophenathroline were secondari ly effective to prevent vanadium uptake. Tiron could not prevent absor ption from VOSO4 as effectively as NaVO3. Deferoxamine was the most ef fective in decreasing the death rate and increasing embryonic growth. Tiron,vas secondarily effective when excessive Tron was administered. Antidotal effectiveness of deferoxamine was observed when it was simul taneously administered with vanadium compounds. Deferoxamine and VOSO4 formed an equimolar complex that is unabsorbable. These results are c omparable with the results shown in previous reports using rats and mi ce. The present experimental system using fertile chick eggs had advan tages in the examination of mineral absorption and in the screening fo r effective antidotes from the viewpoints of ease of experimental proc edure and ani,nal welfare in comparison with conventional methods usin g laboratory animals.