Active Transport of Nicotine by the Isolated Choroid Plexus In Vitro

Abstract

In vitro, the transport of [14C]nicotine into the isolated choroid plexus, the anatomical locus of the blood-CSF barrier, was studied. The isolated rabbit choroid plexus accumulated [14C]nicotine by 2 processes: an active saturable transport process and a nonsaturable process. The [14C]nicotine accumulation process by choroid plexus was not due to binding or intracellular metabolism of the [14C]nicotine. The [14C]nicotine accumulation process in isolated choroid plexus was inhibited by weak bases, including tolazoline and lidocaine, but not by the weak acid probenecid. The accumulation process was decreased 60% by iodoacetate and dinitrophenol and by low temperatures. The choroid plexus concentrated [14C]nicotine in vivo, and may transfer nicotine between blood and CSF in vivo.