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HETEROGENEITY OF HISTAMINE Hi‐RECEPTORS: SPECIES VARIATIONS IN [ 3 H]MEPYRAMINE BINDING OF BRAIN MEMBRANES
Author(s) -
Chang Raymond S. L.,
Tran Vinh Tan,
Snyder Solomon H.
Publication year - 1979
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1979.tb02276.x
Subject(s) - mepyramine , histamine , guinea pig , receptor , chemistry , binding site , histamine h1 receptor , histamine receptor , pharmacology , biochemistry , biology , endocrinology , antagonist
[ 3 H]Mepyramine binds with high affinity to membranes from brain of human, rat, guinea‐pig, rabbit and mouse with drug specificity indicating an association with histamine H 1 receptors. Considerable species differences occur in the affinity of [ 3 H]mepyramine, with guinea‐pig and human having 34 times greater affinity than rat, mouse or rabbit. The greater affinity of [ 3 H]mepyramine in guinea‐pig than in rat is attributable both to faster association and slower dissociation rates in guinea‐pig. Species differences in affinity for H 1 receptor sites occur for some antihistamines but not for others. Some tricyclic antidepressant and neuroleptic drugs are extremely potent inhibitors of [ 3 H]mepyramine binding, exceeding in potency any H 1 antihistamines examined. The tricyclic antidepressant doxepin and the neuroleptic clozapine are the most potent of all drugs examined in competing for [ 3 H]mepyramine binding. The regional distribution of specific [ 3 H]mepyramine binding differs considerably in the various species examined.