Binding of /sup 3/H-acetylcholine to cholinergic receptors in bovine cerebral arteries

Journal Article · Mon Nov 18 00:00:00 EST 1985 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(85)90006-2· OSTI ID:6138596

Shimohama, S; Tsukahara, T; Taniguchi, T; Fujiwara, M

Cholinergic receptor sites in bovine cerebral arteries were analyzed using radioligand binding techniques with the cholinergic agonist, /sup 3/H-acetylcholine (ACh), as the ligand. Specific binding of /sup 3/H-ACh to membrane preparations of bovine cerebral arteries was saturable, of two binding sites, with dissociation constant (K/sub D/) values of 0.32 and 23.7 nM, and maximum binding capacity (Bmax) values of 67 and 252 fmol/mg protein, respectively. Specific binding of /sup 3/H-ACh was displaced effectively by muscarinic cholinergic agents and less effectively by nicotinic cholinergic agents. IC/sub 50/ values of cholinergic drugs for /sup 3/H-ACh binding were as follows: atropine, 38.5 nM; ACh, 59.8 nM; oxotremorine, 293 nM; scopolamine 474 nM; carbamylcholine, 990 nM. IC/sub 50/ values of nicotinic cholinergic agents such as nicotine, cytisine and ..cap alpha..-bungarotoxin exceeded 50 ..mu..M. Choline acetyltransferase activity was 1.09 nmol/mg protein/hour in the cerebral arteries. These findings suggest that the cholinergic nerves innervate the bovine cerebral arteries and that there are at least two classes of ACh binding sites of different affinities on muscarinic reporters in these arteries. 18 references, 2 figures, 2 tables.

• Research Organization: Kyoto Univ., Japan
• OSTI ID: 6138596
• Journal Information: Life Sci.; (United States), Vol. 37:20
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
BIOCHEMICAL REACTION KINETICS
CHOLINE
RECEPTORS
TRANSFERASES
ENZYME ACTIVITY
AFFINITY
ARTERIES
ATROPINE
BRAIN
CATTLE
CELL MEMBRANES
CHEMICAL BONDS
EXPERIMENTAL DATA
LIGANDS
NERVES
NICOTINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALCOHOLS
ALKALOIDS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZINES
AZOLES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
DATA
DOMESTIC ANIMALS
DRUGS
ENZYMES
ESTERS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPOTROPIC FACTORS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
NEUROREGULATORS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PARASYMPATHOLYTICS
PARASYMPATHOMIMETICS
PROTEINS
PYRIDINES
PYRROLES
PYRROLIDINES
QUATERNARY COMPOUNDS
REACTION KINETICS
RUMINANTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques