The role of anion exchange in the uptake of Pb by human erythrocytes and Madin-Darby canine kidney cells

Anion exchange (AE) plays a critical role in regulating intracellular pH in erythrocytes and epithelial cells and has been suggested to facilitate the transport of lead (Pb) across the erythrocyte cell membrane. In this study we examined the role of AE in the uptake of Pb by human erythrocytes and b y Madin-Darby canine kidney (MDCK) cells, the kidney epithelial cell line. Functional AE in MDCK cells was evidenced by: increased uptake of SO42- at pH 6.0 over pH 7.0. and inhibition of SO42- uptake by the AE inhibitor 4, 4 '-diisothiocyanostilbene-2, 2'- disulfonic acid (DIDS) as well as by non-ha lide anions. Accumulation of Pb into MDCK cells was time and temperature de pendent. DIDS inhibited uptake of Pb into human erythrocytes but not MDCK c ells. In conclusion, uptake of Pb into erythrocytes but not kidney epitheli al cells occurs through AE. (C) 2000 Elsevier Science Ireland Ltd. All righ ts reserved.