Table 1

Operational characteristics of histamine receptors

Histamine H1 Most smooth muscle, endothelial cells, adrenal medulla, heart, CNSSmooth muscle contraction, stimulation of NO formation, endothelial cell contraction, increased vascular permeability, stimulation of hormone release, negative inotropism, depolarization (block of leak potassium current) and increased neuronal firing, inositol phospholipid hydrolysis and calcium mobilization, hyperpolarization by Ca2+-dependent potassium currentHistamine1-a 2-[3-(Trifluoromethyl)- phenyl]histamine 2-Thiazolylethylamine 2-Pyridylethylamine 2-MethylhistamineMepyramine (+) and (−)  Chlorpheniramine Triprolidine Temelastine Diphenhydramine Promethazine
Histamine H2 Gastric parietal cells, vascular smooth muscle, suppressor T cells, neutrophils, CNS, heart, uterus (rat)Stimulation of gastric acid secretion, smooth muscle relaxation, stimulation of adenylyl cyclase, positive chronotropic and inotropic effects on cardiac muscle, decreased firing rate, hyperpolarization or facilitation of signal transduction in CNS, block of Ca2+-dependent potassium conductance (I AHP, accommodation of firing, after-hyperpolarization), increase of hyperpolarization-activated current, inhibition of lymphocyte functionHistamine1-a Amthamine Dimaprit Impromidine1-b Arpromidine1-b Cimetidine Ranitidine Tiotidine Zolantidine Famotidine
Histamine H 3 CNS, peripheral nerves (heart, lung, gastrointestinal tract), endothelium, enterochromaffin cellsInhibition of neurotransmitter release, endothelium-dependent relaxation of rabbit middle cerebral artery, inhibition of gastric acid secretion (dog), increase in smooth muscle voltage-dependent Ca2+ current, inhibition of firing of tuberomammilary (histaminergic) neuronsHistamine1-a R-α-methylhistamine Imetit Immepip Nα-methylhistamine1-a Thioperamide Clobenpropit Iodophenpropit Iodoproxyfan
  • CNS, central nervous system.

  • 1-a Nonselective.

  • 1-b H3-antagonist.