Biochem/physiol Actions Sulfobromophthalein (BSP) is a high affinity substrate for organic anion transporting polypeptides (OATPs)1,2 and has been used as a substrate for multidrug resistance associated protein 2 (Mrp2). BSP is transported into hepatocytes by OATPs and, after conjugation to glutathione, is excreted into bile by Mrp2.3 It was found to inhibit the aldo-keto reductase ARK1C20.4 |