These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Nornicotine, a nicotine metabolite and tobacco alkaloid: desensitization of nicotinic receptor-stimulated dopamine release from rat striatum.
    Author: Dwoskin LP, Teng LH, Crooks PA.
    Journal: Eur J Pharmacol; 2001 Sep 28; 428(1):69-79. PubMed ID: 11779039.
    Abstract:
    Nornicotine, a major tobacco alkaloid and nicotine metabolite, accumulates in rat brain in pharmacologically relevant concentrations following repeated nicotine administration. Nornicotine-evoked striatal dopamine release is Ca2+-dependent, stereoselective and sensitive to nicotinic receptor antagonists, indicating nicotinic receptor-mediation. The present study determined if S-(-)-nornicotine desensitizes nicotinic receptors and if cross-desensitization to S-(-)-nicotine occurs. S-(-)-Nicotine (10 and 100 nM) diminished [3H]overflow from [3H]dopamine-preloaded rat striatal slices following subsequent superfusion with 10 microM S-(-)-nicotine (46% and 74%, respectively) or 10 microM S-(-)-nornicotine (59% and 81%, respectively). S-(-)-Nornicotine (1 and 10 microM) diminished the response to subsequent superfusion with 10 microM S-(-)-nornicotine (85% and 97%, respectively) or 10 microM S-(-)-nicotine (82% and 88%, respectively). Thus, similar to S-(-)-nicotine, S-(-)-nornicotine desensitizes nicotinic receptors. but with approximately 12-fold lower potency. Cross-desensitization suggests involvement of common nicotinic receptor subtypes. Therefore, S-(-)-nicotine metabolites, such as nornicotine, have neuropharmacologically relevant effects.
    [Abstract] [Full Text] [Related] [New Search]