Specific 125I-endothelin-1 binding sites in the atrioventricular node of the porcine heart.
The quantitative receptor autoradiographic method we used revealed that specific 125I-endothelin-1 binding sites are highly concentrated in the atrioventricular node of the porcine heart. 125I-Endothelin-1 binding to the atrioventricular node, interatrial and interventricular septa was displaced by unlabeled endothelin-1 with Kd values of 53 pM, 2.03 nM and 3.48 nM, respectively. Knowledge of the existence of specific 125I-endothelin-1 binding sites in the porcine heart helps with understanding the physiology of endothelin, a possible endogenous Ca2+ channel agonist.
Yamasaki
H
H
Department of Pharmacology, Nagasaki University School of Medicine, Japan.
Niwa
M
M
Yamashita
K
K
Kataoka
Y
Y
Shigematsu
K
K
Hashiba
K
K
Ozaki
M
M
D000818:Animals; D001283:Atrioventricular Node / Q000378:metabolism / Q000648:ultrastructure*; D001345:Autoradiography; D001665:Binding Sites; D016232:Endothelins; D006329:Heart Conduction System / Q000648:ultrastructure*; D007457:Iodine Radioisotopes; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism / Q000648:ultrastructure; D010455:Peptides / Q000378:metabolism*; D013552:Swine
D016232:Endothelins; D007457:Iodine Radioisotopes; D010455:Peptides