Mediates tubular uptake of organic compounds from circulation. Mediates the influx of agmatine, serotonin, choline, ranitidine, histamine, creatinine, amantadine, memantine, acriflavine, 4-[4-(dimethylamino)-styryl]-N-methylpyridinium ASP and amiloride (By similarity). Mediates the influx of adrenaline, noradrenaline (norepinephrine), dopamine, cimetidine, famotidine, metformin, N-1-methylnicotinamide (NMN), 1-methyl-4-phenylpyridinium (MPP), tetraethylammonium (TEA), oxaliplatin and cisplatin. Cisplatin may develop a nephrotoxic action. Transport of creatinine is inhibited by fluoroquinolones such as DX-619 and LVFX. This transporter is a major determinant of the anticancer activity of oxaliplatin and may contribute to antitumor specificity. Expressed in the kidney; in the proximal tubule of the outer medulla. Expression is greater in the kidney of male than of female. Down-regulated in ischemia/reperfusion (I/R) kidneys. Up-regulated by testosterone and moderately down-regulated by estradiol. Belongs to the major facilitator (TC 2.A.1) superfamily. Organic cation transporter (TC 2.A.1.19) family.