Characterization of the beta 2 adrenoceptors of dog liver.
The beta-adrenoceptors present in dog liver were characterized by radioligand binding techniques. [3H]Dihydroalprenolol bound with high affinity (KD 0.9 nM) to a relatively low number of sites (approximately 68 fmol/mg protein) in partially purified dog liver plasma membranes. These sites were characterized by binding competition; the orders of affinity were: (a) for agonists: (-)isoproterenol > or = salbutamol > epinephrine > or = terbutaline > norepinephrine > (+)isoproterenol and (b) for antagonists: propranolol > ICI 118551 >> metoprolol >> atenolol. These data indicate that dog liver expresses beta-adrenoceptors of the beta2 subtype.
García-Sáinz
J A
JA
Instituto De Fisiología Celular, Universidad Nacional Autónoma De México, D.F. agarcia@ifcsunl.ifisiol.unam.mx
Cruz-Muñoz
M E
ME
Romero-Avila
M T
MT
D000318:Adrenergic beta-Agonists / Q000378:metabolism*; D000319:Adrenergic beta-Antagonists / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D004082:Dihydroalprenolol / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D007553:Isotope Labeling; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008297:Male; D011869:Radioligand Assay; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014316:Tritium
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D018343:Receptors, Adrenergic, beta-2; D014316:Tritium; D004082:Dihydroalprenolol