Effects of antidepressants on histamine H1 and muscarinic acetylcholine receptors in guinea-pig ileum.
The properties of some tricyclic and non-tricyclic antidepressants on antagonist histamine H1 and muscarinic acetylcholine receptors have been evaluated on guinea-pig ileum. They act like competitive antagonists on histamine H1 receptors. Some of them show a competitive antagonism and others a non-competitive antagonism on muscarinic acetylcholine receptors. A few of them are very potent antagonists on histamine H1 and/or muscarinic acetylcholine receptors, while others, especially the non-tricyclic antidepressants, have a small potency. All antidepressants have a higher histamine H1 activity than muscarinic acetylcholine activity. These results cannot explain the therapeutic effect of these drugs, but they can account for some side effects and drug interactions.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology*; D005260:Female; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics; D011968:Receptors, Histamine / Q000187:drug effects*; D011969:Receptors, Histamine H1 / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects*
D000928:Antidepressive Agents; D010276:Parasympatholytics; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011976:Receptors, Muscarinic; D006632:Histamine; D000109:Acetylcholine