Studies on the oxidation-reduction properties of. beta. -adrenergic drugs. An approach to explain the differences between agonists and antagonists
The role of the substituent on the phenyl ring of the ..beta..-adrenergic drugs in the interaction with the receptor was investigated. The abilities of 50 compounds to compete for the (/sup 3/H) dihydroalprenolol binding sites and to stimulate adenylate cyclase were determined in frog erythrocyte membranes, which possess characteristics of B-2 adrenergic receptors. The structure-activity relationship was studied by comparing their oxidation peak potential ()Ep) vs. Ag/AgCl) with their binding affinities (K/sub d/) and intrinsic activities (IA, maximum ability to stimulate adenylate cyclase). The structures of ..beta..-agonists and antagonists tested were closely related. There were derivatives of ethanolamine or of oxypropanolamine. Both the IA and Ep were determined primarily by the nature of the substituents on the phenyl ring. The ethanolamine side chain was redox inactive and was essentially associable with their binding affinities to the receptors. All the antagonists tested (28) exhibited Ep greater than or equal to 0.75, suggesting that they were difficult to oxidize. Agonsits, however, exhibited a wide range of Ep (0.3-0.7V). Drugs that had low Ep (0.25-0.4V) showed high IA (greater than or equal to 0.8, isoproterenol as 1). Therefore, it is proposed that the oxidizing tendency of the meta-substitutent on the phenyl ring is one of the factors that influences the IA.
- Research Organization:
- SK and F Labs., Swedeland, PA
- OSTI ID:
- 5393421
- Report Number(s):
- CONF-8604222-; TRN: 86-028349
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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CYCLASES
ENZYME ACTIVITY
RECEPTORS
BIOCHEMICAL REACTION KINETICS
SYMPATHOMIMETICS
REDOX REACTIONS
AFFINITY
CELL MEMBRANES
ERYTHROCYTES
FROGS
STRUCTURE-ACTIVITY RELATIONSHIPS
TRITIUM COMPOUNDS
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
DRUGS
ENZYMES
KINETICS
LABELLED COMPOUNDS
LYASES
MATERIALS
MEMBRANE PROTEINS
MEMBRANES
ORGANIC COMPOUNDS
PROTEINS
REACTION KINETICS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques