Biochemical, cellular, and pharmacological aspects of the multidrug transporter

Considerable evidence has accumulated indicating that the multidrug transpo rter or P-glycoprotein plays a role in the development of simultaneous resi stance to multiple cytotoxic drugs in cancer cells. In recent years, variou s approaches such as mutational analyses and biochemical and pharmacologica l characterization have yielded significant information about the relations hip of structure and function of P-glycoprotein. However, there is still co nsiderable controversy about the mechanism of action of this efflux pump an d its function in normal cells. This review summarizes current research on the structure-function analysis of P-glycoprotein, its mechanism of action, and facts and speculations about ifs normal physiological role.