CARRIER-MEDIATED SYSTEM FOR PEFLOXACIN UPTAKE IN HUMAN MONOCYTES

Protein transporters present in cellular membranes can influence the i ntracellular concentration of a variety of drugs. Pefloxacin is a fluo roquinolone which is commonly used in systemic infections. Its transpo rt mechanisms have never been described. In the present study, we demo nstrated that pefloxacin uptake is carrier-mediated. Pefloxacin crosse s the membrane in zwitterionic form. The transport seems to differ fro m that of other fluoroquinolones which use amino acid or organic anion transporters. Pefloxacin uptake is not influenced by the presence of hexose in the incubation medium. It does not use a nucleoside transpor t system to penetrate the cells but adenosine increases the uptake. Th e carrier is inhibited by verapamil at 60 min and is activated by a Ca 2+-dependent system.