Primary Structure and Functional Expression of the Apical Organic Cation Transporter from Kidney Epithelial LLC-PK1Cells

摘要: Renal secretion of organic cations involves at least two distinct transporters, located in the basolateral and apical membranes proximal tubule cells. Whereas transporter has recently been cloned, sequence information about type was not yet available. An cation transporter, OCT2p, cloned from LLC-PK1 cells, a porcine cell line with properties tubular epithelial OCT2p heterologously expressed characterized human embryonic kidney 293 OCT2p-mediated uptake prototypical [14C]tetraethylammonium ([14C]TEA) into cells saturable. There highly significant correlation between Ki values for inhibition [14C]TEA transfected (r = 0.995; p < 0.001; n 6). Although is structurally related to OCT1r, rat kidney, transporters could be clearly discriminated pharmacologically corticosterone, decynium22, O-methylisoprenaline. The findings hand suggest that OCT2 corresponds transporter. Reverse transcriptase-polymerase chain reaction indicates mRNA OCT1r limited non-neuronal tissue, whereas OCT2r, homologue rat, found both central nervous regions known rich monoamine transmitter dopamine.