Retinol-binding protein and beta 2-microglobulin in urine of cadmium-fed rhesus monkeys.

Retinol-binding protein (RBP) in the Rhesus monkey had the same electrophoretic mobility, molecular weight, and common antigens as human RBP; beta 2-microglobulin protein (MG) had similar electrophoretic mobility and partial common antigens to human MG. After a prolonged oral administration of cadmium chloride to 10 monkeys over a period of 55 weeks, one monkey of the 30 mg Cd/day group indicated RBPuria and MGuria with the use of anti-human RBP and MG sera when proteinuria appeared. The immunological assay of low-molecular-weight proteins in urine was not applicable for the early detection of cadmium health effects in monkeys.