title: Agonist-antagonist interactions at angiotensin receptors: application of a two-state receptor model.
abstract: Interactions between agonists and antagonists at angiotensin receptors are characterized by a number of features: variation of antagonist dynamics between apparent simple competition, insurmountable antagonism and, occasionally, augmentation; the tendency for insurmountable antagonism to be saturable; slow recovery of agonist responses following agonist-induced tachyphylaxis; and the ability of competitive antagonists to accelerate recovery from the latter intervention. Some of these phenomena have also been observed in studies of 5-HT2 receptors where they were attributed to the operation of a two-state model with an allosteric site. In this article, Mark Robertson and colleagues propose that the properties of angiotensin AT1 receptors may be explained by a similar model, but without the need to evoke an allosteric site.
authors: Department of Pharmacology, Fisons, Loughborough, Leicestershire, UK.
authors: M J
authors: MJ
authors: Robertson
authors: I G
authors: IG
authors: Dougall
authors: D
authors: D
authors: Harper
authors: K C
authors: KC
authors: McKechnie
authors: P
authors: P
authors: Leff
mesh_terms: D000804:Angiotensin II / Q000037:antagonists & inhibitors; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001713:Biphenyl Compounds / Q000494:pharmacology; D003198:Computer Simulation; D004347:Drug Interactions; D007093:Imidazoles / Q000494:pharmacology; D019808:Losartan; D008954:Models, Biological; D011945:Receptors, Angiotensin / Q000819:agonists*; D013618:Tachyphylaxis; D013777:Tetrazoles / Q000494:pharmacology
chemical_list: D057911:Angiotensin Receptor Antagonists; D001713:Biphenyl Compounds; D007093:Imidazoles; D011945:Receptors, Angiotensin; D013777:Tetrazoles; D000804:Angiotensin II; D019808:Losartan