Abstract
Since metallothionein binds strongly with cadmium at a definite molar ratio, an examination was made on the method for quantitative determination of metallothionein using this characteristic. 1) Free cadmium was removed by heating with a guinea pig hemolysate and subsequent separation by centrifugation. 2) Zinc in the metallothionein fraction was completely substituted with cadmium by its addition and treatment of this fraction with the guinea pig hemolysate resulted in approximately complete removal of cadmium other than that in the metallothionein fraction. 3) This method showed a good linearity in the wide range of cadmium content of 0.2 to 4.0 μg/ml. 4) Result obtained from this method was compared with the existing method of measuring the amount of metal (s) bound to the metallothionein fraction after gel filtration in the liver and kidneys of rats given cadmium, and the values were in approximate agreement. Correlation coefficient was 0.98 for the liver and 0.95 for the kidneys.
