Sine 1972 we have examined renal functions of the residents in the area polluted by cadmium at Kosaka town, Akita prefecture, Japan. We have found 10 patients with multiple proximal tubular dysfunctions due to chronic cadmium poisoning among total 110 residents. We reported previously that the charactarization of tubular proteinuria by polyacrylamlde gel zone electrophoresis, and generalized aminoaciduria by thin layer chromatography were the most valuable screening test for the detection of multiple proximal tubular dysf unctons. In the present study, urinary retinol-binding protein were estimated by the methods of counter immunoelectrophoresis in the above mentioned residents. The estimation of urinary retinol-binding protein was no less significant than urinary protein zone electrophoresis and urinary aminoacid analysis as the screening test for the detection of mu-ltiple proximal tubular dysfunctions. Counter immunoelectrophoresis was much easier than the former two methods in the handling and could treat large number of urine samples without timewaste. Therefore, we concluded that the estimation of urinary retinol-binding protein by counter im-munoelectrophoresis was the first choice of screening test for the detection of chronic cadmium nephropathy among the residents in the area polluted by cadmium.
