Binding of agonists and antagonists to the porcine adipose tissue beta-adrenergic receptor(s).
1. Affinities of agonists for porcine adipose tissue beta-adrenergic receptors, determined by competitive ligand binding with 3H-dihydroalprenolol to crude adipose tissue membranes in vitro, varied from 50 times > to 25 times < than isoproterenol. Affinities for antagonists varied from 8 times > to 1000 times < propranolol. 2. Receptor affinity was not related to the ability to stimulate or inhibit lipolysis, or to the agonist or antagonist purported receptor subtype specificity. 3. Modeling of ligand-binding data indicated more than one binding site for several ligands. The assignment of beta-adrenergic subtypes to the individual binding sites was unclear because this would depend on the individual ligands used to establish binding sites.
Mersmann
H J
HJ
USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030.
Akanbi
K
K
Shparber
A
A
McNeel
R L
RL
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000318:Adrenergic beta-Agonists / Q000493:pharmacokinetics* / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000493:pharmacokinetics* / Q000494:pharmacology; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D004082:Dihydroalprenolol; D066298:In Vitro Techniques; D008024:Ligands; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D013552:Swine
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D008024:Ligands; D004082:Dihydroalprenolol