Active transport of high-affinity choline and nicotine analogs into the central nervous system by the blood-brain barrier choline transporter

David D. Allen, Paul R. Lockman, Karen E. Roder, Linda P. Dwoskin, Peter A. Crooks

Research output: Contribution to journalArticlepeer-review

61 Scopus citations

Abstract

Cigarette smoking is strongly implicated in the development of cardiovascular disorders. Recently identified nicotinium analogs may have therapeutic benefit as smoking cessation therapies but may have restricted entry into the central nervous system by the blood-brain barrier (BBB) due to their physicochemical properties. Using the in situ perfusion technique, lobeline, choline, and nicotinium analogs were evaluated for binding to the BBB choline transporter. Calculated apparent Ki values for the choline transporter were 1.7 μM N-n-octyl choline, 2.2 μM N-n-hexyl choline, 27 μM N-n-decylnicotinium iodide, 31.9 μM N-n-octylpyridinium iodide, 49 μM N-n-octylnicotinium iodide (NONI), 393 μM lobeline, and ≥ 1000 μM N-methylnicotinium iodide. Nicotine and N-methylpyridinium iodide, however, do not apparently interact with the BBB choline transporter. Given NONI's apparent Ki value determined in this study and its ability to inhibit nicotine-evoked dopamine release from superfused rat brain slices, potential brain entry of NONI via the BBB choline transporter was evaluated. [3H]NONI exhibited a BBB transfer coefficient value of ∼1.6 x 10-3 ml/s/g and a Km of ∼250 μM. Unlabeled choline addition to the perfusion fluid reduced [3H]NONI brain uptake. We hypothesize the N-n-octyl group on the pyridinium nitrogen of NONI facilitates brain entry via the BBB choline transporter. Thus, NONI may have utility as a smoking cessation agent, given its ability to inhibit nAChRs mediating nicotine-evoked dopamine release centrally, and to be distributed to brain via the BBB choline transpoter.

Original languageEnglish
Pages (from-to)1268-1274
Number of pages7
JournalJournal of Pharmacology and Experimental Therapeutics
Volume304
Issue number3
DOIs
StatePublished - Mar 1 2003

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology

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