Antidepressants are weak competitive antagonists of histamine H2 receptors in dissociated brain tissue.
Guinea pig hippocampus dissociated by mechanical means into uniform clumps of cells (approximately 100 micron in diameter) contains histamine receptors (H1 and H2) which mediate the formation of cyclic AMP. In this preparation, antidepressants are very potent antagonists of histamine H1 receptors but are weak antagonists of histamine H2 receptors. The latter result is contrary to data derived by others using homogenates of the guinea pig hippocampus and seems to dispel the idea that antidepressants derive their efficacy by blocking histamine H2 receptors in brain.
D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D001667:Binding, Competitive; D001921:Brain / Q000187:drug effects*; D000242:Cyclic AMP / Q000378:metabolism; D006168:Guinea Pigs; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D066298:In Vitro Techniques; D014299:Trimipramine / Q000378:metabolism
D000928:Antidepressive Agents; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D014299:Trimipramine; D000242:Cyclic AMP