TABLE 1

Summary of the pharmacological effects mediated by imidazoline receptors

Receptor TypeCommon LigandsPharmacological Effects
Cellular EffectCellular ActionIn Vivo EffectIn Vivo Action
I1LNP509, LNP599, LNP91, LNP911Cell viabilityIs antiproliferative; protects cell viabilityBlood pressureReduces blood pressure and heart rate
Insulin and adiponectinStimulates the secretion of adiponectin; increases insulin sensitivity; is insulinotropicHeart arrhythmiaHas an antiarrhythmic effect
NeuronsIncreases MAPK activity; decreases GABAA receptor–mediated inhibitory postsynaptic currentsHeart failureImproves cardiac performance in congestive heart failure; prevents ventral hypertrophy
Glucose and lipid metabolismReduces insulin resistance, hyperinsulinemia, hypertension, and metabolic syndrome
I22-BFI, BU224, CR4056, tracizoline, idazoxan, phenyzolinePainIs antinociceptive in multiple models of chronic pain; enhances the antinociceptive effects of opioids; reduces antinociceptive tolerance and physical dependence of opioids
Subjective effectsProduces characteristic discriminative stimulus effects specific to I2 receptor activation
NeuroprotectionIs neuroprotective in a rat cerebral ischemia model
Body temperatureReduces body temperature and may involve temperature regulation
I3KU-14RInsulin secretionFacilitates insulin secretion