Short communication
Characteristics of [3H]mepyramine binding in DDT1MF-2 cells: Evidence for high affinity binding to a functional histamine H1 receptor

https://doi.org/10.1016/0922-4106(94)90196-1Get rights and content

Abstract

The binding characteristics of [3H]mepyramine to histamine H1 receptors in the smooth muscle cell line, DDT1MF-2, have been investigated. Competition binding experiments produced dissociation constants (Ki) for mepyramine, (+)-chlorpheniramine, and promethazine of 3.4 nM, 2.6 nM and 0.66 nM, respectively. Saturation binding using [3H]mepyramine produced a Kd of 2.1 nM and a Bmax of 47 fmol/mg protein. These data suggest that a high-affinity [3H]mepyramine binding site can be detected with the characteristics of the “classical” histamine H1 receptor. The low-affinity [3H]mepyramine binding site reported previously [Mitsuhashi, M. and Payan, D.G. (1988) J. Cell. Physiol. 134, 367–375] is predominantly to a secondary [3H]mepyramine site. The “low affinity” or secondary [3H]mepyramine binding site on DDT1MF-2 cells is insensitive to quinine (10 μM) and is therefore distinct from the [3H]mepyramine binding protein found in rat liver.

References (15)

There are more references available in the full text version of this article.

Cited by (7)

  • Biological and pharmacological aspects of histamine receptors and their ligands

    2011, Biomedical Aspects of Histamine: Current Perspectives
View all citing articles on Scopus
View full text