Effects of antidepressants on histamine H2 receptors in rat isolated uterus

The antagonist effect of various antidepressants, both tricyclic and non-tricyclic, and of thiothixene on the histamine H2 receptors has been studied in the rat isolated uterus. All the drugs studied inhibit the effect of histamine, acting as competitive antagonists. Trimipramine and mianserin were the antidepressants which showed the highest activity, superior to cimetidine, whereas nomifensine, viloxazine, trazodone and maprotiline were those which showed the lowest antihistamine H2 activity. These results suggest that there is an interaction between antidepressants and histamine H2 receptors in rat isolated uterus similar to the interaction existing between antidepressants and histamine H2 receptors in brain and other tissues.