Angiotensin II binding activity in cultured porcine arterial endothelial cells.
Angiotensin II (A II) binding activity was detected in the particulate fraction (100,000 g, 60 min precipitate) of cultured porcine aortic endothelial cells. Scatchard analysis of the binding activity indicated a single class of binding sites with a dissociation constant (Kd) of 1.1 nM and a total binding capacity (Bmax) of 125 fmol/mg protein. The binding of [125I]A II was inhibited by excess unlabelled A II, A II analogues ([Sar1, Ile8]A II and [Sar1, Ala8]A II), A I (angiotensin I) and A III (angiotensin III), but not by bradykinin. Type specific A II receptor antagonists, losartan (type 1 angiotensin II receptor) and PD123319 (type 2 angiotensin II receptor), did not inhibit the binding. These results suggest that the A II specific binding protein(s) or receptor(s) is present in arterial endothelial cells, and that it is different from typical type 1 and type 2 angiotensin II receptors.
Mineo
C
C
Faculty of Pharmaceutical Sciences, Teikyo University, Kanagawa, Japan.
Shimizu
H
H
Takada
K
K
Imanaka
T
T
Takano
T
T
D000804:Angiotensin II / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism*; D001665:Binding Sites; D001713:Biphenyl Compounds / Q000494:pharmacology; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D007093:Imidazoles / Q000494:pharmacology; D019808:Losartan; D011725:Pyridines / Q000494:pharmacology; D013552:Swine; D013777:Tetrazoles / Q000494:pharmacology
D057911:Angiotensin Receptor Antagonists; D001713:Biphenyl Compounds; D007093:Imidazoles; D011725:Pyridines; D013777:Tetrazoles; D000804:Angiotensin II; C073402:PD 123319; D019808:Losartan