1. Action of histamine and antihistamines on the H1 receptor
Action of histamine and antihistamines on the H1 receptor. Molecular basis of action of histamine and antihistamines. (A) The inactive state of the histamine H1 receptor is in equilibrium with the active state. (B) The agonist, histamine, has preferential affinity for the active state, stabilizes the receptor in this conformation, and shifts the equilibrium toward the active state. (C) An H1 antihistamine (inverse agonist) has preferential affinity for the inactive state, stabilizes the receptor in this conformation, and shifts the equilibrium toward the inactive state. GDP = guanosine diphosphate; GTP = guanosine triphosphate. (Reproduced with permission from Simons FE, Simons KJ: Histamine and H1-antihistamine: celebrating a century of progress. J Allergy Clin Immunol. 2011;128:1139–1150. Copyright Elsevier.)
Source: Pharmaceuticals, Goldfrank's Toxicologic Emergencies, 10e
Citation: Hoffman RS, Howland M, Lewin NA, Nelson LS, Goldfrank LR. Goldfrank's Toxicologic Emergencies, 10e; 2015 Available at: Accessed: October 13, 2017
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