Abstract
The blockade of choroid plexus systems which transport penicillin, p-aminosalicylic acid (PAS) and iodide was studied in vitro and in vivo. In vitro, the transport into choroid plexus of penicillin and p-aminosalicylic acid but not of iodide was inhibited by salicylate and probenecid. In vivo, in animals subjected to ventriculocisternal perfusions, the transport from cerebrospinal fluid (CSF) to blood of p-aminosalicylic acid and penicillin but not of iodide was decreased by salicylate. These results confirm the conclusion that iodide is transported from the CSF on a carrier distinct from the weak carboxylic acid carrier. In unanesthetized animals which were subjected to a constant intravenous infusion of penicillin, but not subjected to CSF perfusion, pretreatment with intraperitoneal salicylate or probenecid increased the concentration of penicillin in the CSF. The increase in CSF penicillin induced by probenecid was due to the combined blockade of the active transport systems for penicillin in choroid plexus and kidney.
Footnotes
- Received April 20, 1973.
- Accepted August 6, 1973.
- © 1974 by The Williams & Wilkins Company