A methylsulphonyl metabolite of a polychlorinated biphenyl can serve as a ligand for α_2μ-globulin in rat and major-urinary-protein in mice

Abstract

1. Kidneys from rats given an intraperitoneal dose of 4,4'-bis([³H]methylsulphonyl)-2,2',5,5'-tetrachlorobiphenyl [(CT₃S0₂)2TCB)] contained (CT₃S0₂)2TCB associated with a protein which has been isolated and characterized by SDS-polyacrylamide gel electrophoresis (SDS-PAGE), immunoblot and immunodiffusion analysis to be α_2μ-globulin (α_2μ).

2. The same radioactive α_2μ-globulin complex was isolated from urine of rats given an i.p. dose of (CT₃S0₂)₂TCB. This complex represented 12.3% (0.27% dose) and 9.3% (0.06% dose) of the radioactivity excreted in 0.24 h and 24-48 h urine, respectively.

3. The radioactivity was extractable from α_2μ and characterized by t.l.c. (co-chromatography in two solvent systems) to be (CT₃S0₂)₂TCB.

4. A radioactive-protein complex was isolated from urine of mice given an i.p. dose of (CT₃S0₂)₂TCB. The radioactive-protein complex was characterized to be mouse major urinary protein (MUP) by SDS-PAGE, immunoblot and immunodiffusion analysis. This complex was not detected in mouse kidney.

5. Urinary excretion of radioactive-MUP complex represented 51.7% (2.3% dose) and 28% (1.3% dose) of the radioactivity excreted in 0.24 h and 24-48 h urine, respectively.