ABC transporters and p-glycoprotein transporters (mulitdrug resistance protein)
Cell efflux pump pumps drugs out in cancer bacteria and normal cells
P-glycoprotein transporters
GI epithelium
Pumps xenobiotics into intestinal lumen
Liver
Pumps xenobiotics into bile ducts cleared into lumen
Proximal tubule of kidney
Pumps XB into piss
Blood brain barrier
XB back into capillaries out of brain
Cancer cells
Large amounts of P-gp which renders them multidrug resistant
We have drugs that increase activity of P-gp (rifampicin) and decrease activity (verapamil)