MDR EXPRESSION IN NORMAL-TISSUES - PHARMACOLOGICAL IMPLICATIONS FOR THE CLINICAL USE OF P-GLYCOPROTEIN INHIBITORS

In multidrug resistance, the MDR1 gene product, P-glycoprotein (P-gp) is thought to function as an efflux transport pump with broad specific ity for a variety of anticancer drugs. The distribution of Pgp express ion in normal human tissues with secretory function suggests P-gp may have a number of physiologic roles and that impeding P-gp function in these tissues with MDX modulators could result in increased cytotoxin concentrations and enhanced toxicity.