Comparison, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, of urinary proteins excreted by workers exposed to cadmium, mercury or lead.

Urinary proteins from workers exposed to cadmium (Cd, n = 20), lead (Pb, n = 19) or mercury (Hg, n = 25) were analyzed by polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS). The areas of the peaks with the relative mobilities of beta 2-microglobulin and retinol binding protein (low molecular weight proteins), albumins, transferrin and IgG (high molecular weight proteins) were measured and compared with those obtained in matched control groups. The concentrations (mean and range) of the metals in blood (B, micrograms/100 ml) and in urine (U, micrograms/g creatinine) of the exposed groups were as follows: Cd group, CD-B = 1.51 (0.18-4.31) and CD-U = 16.6 (2.08-59.3); Pb group, Pb-B = 44.5 (44.8-61.3) and Pb-U = 88.7 (15.2-298); Hg group, Hg-B = 3.74 (1.84-8.14) and Hg-U = 116 (51.8-206). The average duration of exposure to the metal was 30.5 (Cd), 12.5 (Pb) and 7.2 (Hg) years respectively. Under these exposure conditions, it was found that Cd increases the urinary excretion of low as well as high molecular weight proteins, Hg induces an increased urinary excretion of only high molecular weight proteins and lead has no significant effect on the renal excretion of either type of protein.