Speth R C, Kim K H
Department of Veterinary and Comparative Anatomy, Washington State University, Pullman 99164.
Biochem Biophys Res Commun. 1990 Jun 29;169(3):997-1006. doi: 10.1016/0006-291x(90)91993-3.
Angiotensin II receptor binding sites in rat liver and PC12 cells differ in their affinities for a nonpeptidic antagonist, DuP 753, and p-aminophenylalanine6 angiotensin II. In liver, which primarily contains the sulfhydryl reducing agent-inhibited type of angiotensin II receptor, which we refer to as the AII alpha subtype, DuP 753 displays an IC50 of 55 nM, while p-aminophenylalanine6 angiotensin II displays an IC50 of 8-9 microM. In PC12 cells, which primarily contain the angiotensin II receptor type whose binding affinity is enhanced by sulfhydryl reducing agents (AII beta), DuP 753 displays an IC50 in excess of 100 microM, while p-aminophenylalanine6 angiotensin II displays an IC50 of 12 nM. p-Aminophenylalanine6 angiotensin II binding affinity in liver is decreased in the presence of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) suggesting that this analogue is an agonist.
大鼠肝脏和PC12细胞中的血管紧张素II受体结合位点对非肽类拮抗剂DuP 753和对氨基苯丙氨酸6血管紧张素II的亲和力不同。在主要含有巯基还原剂抑制型血管紧张素II受体（我们称之为AIIα亚型）的肝脏中，DuP 753的IC50为55 nM，而对氨基苯丙氨酸6血管紧张素II的IC50为8 - 9 μM。在主要含有巯基还原剂增强其结合亲和力的血管紧张素II受体类型（AIIβ）的PC12细胞中，DuP 753的IC50超过100 μM，而对氨基苯丙氨酸6血管紧张素II的IC50为12 nM。在鸟苷5'-O-(3-硫代三磷酸)(GTPγS)存在的情况下，肝脏中对氨基苯丙氨酸6血管紧张素II的结合亲和力降低，表明该类似物是一种激动剂。
