Expression and immunolocalization of multidrug resistance protein 2 in rabbit small intestine

Multidrug resistance protein 2 (MRP2) is an ATP-dependent transporter of an ionic drugs and conjugates. It functions as an efflux pump in the apical me mbranes of liver and kidney cells, but its membrane localization in small i ntestine has not yet been defined. The present study demonstrates exclusive localization of Mrp2 to the brush-border (apical) membrane of villi, decre asing in intensity from the villus tip to the crypts. In immunoblot analysi s of crude membranes of various rabbit tissues, Mrp2 was only found in smal l intestine, kidney and liver. These results are in-line with the supposed function of Mrp2 in drug excretion. (C) 2000 Elsevier Science B.V. All righ ts reserved.