Binding of [3H]cirazoline to an imidazoline site in rat brain and kidney membranes.
Two classes of high-affinity sites for [3H]cirazoline were characterized in rat brain and kidney membranes. In both tissues, the binding parameters for the high- and low-affinity sites are similar with Bmax values of approximately 50 fmol/mg protein, Kd approximately 0.6 nM and Bmax approximately 470 fmol/mg protein, Kd approximately 11 nM respectively. Inhibition studies of [3H]cirazoline binding to the lower affinity site revealed that only guanidinium or imidazoline derivatives compete with the specific binding of this radioligand. Our results suggest that [3H]cirazoline could be used as a novel ligand to label the non-adrenergic imidazoline-preferring sites.
Le Rouzic
M
M
Synthelabo Research, Department of Preclinical Research, Bagneux, France.
Angel
I
I
Schoemaker
H
H
Allen
J
J
Arbilla
S
S
Langer
S Z
SZ
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism* / Q000648:ultrastructure; D006146:Guanidines / Q000378:metabolism; D007093:Imidazoles / Q000378:metabolism*; D054755:Imidazoline Receptors; D007668:Kidney / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000378:metabolism / Q000648:ultrastructure; D010627:Phenethylamines / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000378:metabolism*; D012680:Sensitivity and Specificity; D014316:Tritium
D006146:Guanidines; D007093:Imidazoles; D054755:Imidazoline Receptors; D010627:Phenethylamines; D011955:Receptors, Drug; D014316:Tritium; C014282:cirazoline