TRANSPORT OF PARAQUAT BY A RENAL EPITHELIAL-CELL LINE, MDCK

Transport of paraquat (Pe), a herbicidal cation, was previously invest igated in a proximal (LLC-PK1) renal epithelial cell line using permea ble collagen-coated filters. Pe was actively transported from the baso lateral side via a cation transport system by the LLC-PK1 cells. In th e present study, the transport of PQ was investigated in a distal rena l epithelial cell line, MDCK. Pe was predominantly transported from th e basolateral to apical (B to A) side. The basolateral transport of Pe in MDCK cells was not saturable with increasing concentrations and no t energy dependent. The flux and uptake of Pe was much lower in the MD CK than LLC-PK1 cells. It is concluded that MDCK, a distal renal tubul ar cell line, does not have an active transport system for PQ.