a difference in the mechanism of transmembrane transport was demonstrated for methotrexate ( mtx ) and mtx bound to the high molecular weight carrier bovine serum albumin ( mtx-bsa ) when the drug dose needed to reduce growth of cells to 50 % of that of untreated cells ( id50 ) was compared in the sensitive l1210 leukemia and 3 l1210 sublines resistant to mtx by virtue of either deficient mtx transport or high levels of dihydrofolate dehydrogenase ( dhfd ) .
C1519624
transmembrane transport
C0007634
cells