KINETIC TRANSPORT ANALYSIS OF DAUNORUBICIN BY LOVO AND LOVO DX CELLS/

We describe a fluorometric technique for the measurement of transport parameters of fluorescent drugs through cellular membranes, Unlike oth er procedures, this method gives an accurate measure of drug accumulat ed in the cells and measures the fraction of free and bound drug in th e cell. The kinetic parameters of transport through cellular membranes are determined using a simple three-compartment model combined with f luorescence measurements performed on the extracellular medium and on Triton-permeabilized cells during daunorubicin incorporation, With thi s technique we found that LoVo cells have a greater daunorubicin uptak e, a similar input rate constant and a lower output rate constant than the drug-resistant LoVo/DX cells.