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: [3H]doxepin interactions with histamine H1-receptors and other sites in guinea pig and rat brain homogenates.
    Author: Tran VT, Lebovitz R, Toll L, Snyder SH.
    Journal: Eur J Pharmacol; 1981 Apr 09; 70(4):501-9. PubMed ID: 7238574.
    Abstract:
    [3H]Doxepin, a tricyclic antidepressant, binds to brain homogenates with two saturable components. The high affinity component, with a dissociation constant (KD) of 0.26 nM, is associated with histamine H1-receptors. This high affinity binding shows stereospecificity in that d-chlorpheniramine is 100 times more potent than the pharmacologically less active l-isomer. Its drug specificity and regional variation closely parallel those exhibited by [3H]mepyramine binding. The drug specificity of the low affinity component is distinct from that of histamine H1-receptors, with no stereospecificity for chlorpheniramine isomers. Furthermore, all the H1-histamine antagonists tested display micromolar potency at the low-affinity doxepin sites but nanomolar potency at the high-affinity doxepin sites associated with a physiological histamine H1-receptor. The drug specificity of the low affinity site does not correspond to that of any known neurotransmitter receptor. Tricyclic antidepressants display IC50 values of 30-600 nM for the inhibition of [3H]doxepin binding to the low-affinity component with most values in the 0.1-0.3 microM affinity range.
    [Abstract] [Full Text] [Related] [New Search]