Biomaterial Database

Solubilized rat brain adenosine receptors have two high-affinity binding sites for 1,3-dipropyl-8-cyclopentylxanthine. 1991

J C Oliveira, and A M Sebastião, and J A Ribeiro

Laboratory of Pharmacology, Gulbenkian Institute of Science, Oeiras, Portugal.

The specific binding of L-N6-[3H]phenylisopropyladenosine (L-[3H]PIA) to solubilized receptors from rat brain membranes was studied. The interaction of these receptors with relatively low concentrations of L-[3H]PIA (0.5-12.0 nM) in the presence of Mg2+ showed the existence of two binding sites for this agonist, with respective dissociation constant (KD) values of 0.24 and 3.56 nM and respective receptor number (Bmax) values of 0.28 +/- 0.03 and 0.66 +/- 0.05 pmol/mg of protein. In the presence of GTP, the binding of L-[3H]PIA also showed two sites with KD values of 24.7 and 811.5 nM and Bmax values of 0.27 +/- 0.09 and 0.93 +/- 0.28 pmol/mg of protein for the first and the second binding site, respectively. Inhibition of specific L-[3H]PIA binding by 1,3-dipropyl-8-cyclopentylxanthine (DPCPX) (0.1-300 nM) performed with the same preparations revealed two DPCPX binding sites with Ki values of 0.29 and 13.5 nM, respectively. [3H]DPCPX saturation binding experiments also showed two binding sites with respective KD values of 0.81 and 10.7 nM and respective Bmax values of 0.19 +/- 0.02 and 0.74 +/- 0.06 pmol/mg of protein. The results suggest that solubilized membranes from rat brain possess two adenosine receptor subtypes: one of high affinity with characteristics of the A1 subtype and another with lower affinity with characteristics of the A3 subtype of adenosine receptor.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D010660	Phenylisopropyladenosine	N-Isopropyl-N-phenyl-adenosine. Antilipemic agent. Synonym: TH 162.	Isopropylphenyladenosine,L-Phenylisopropyladenosine,N(6)-Phenylisopropyl-Adenosine,L Phenylisopropyladenosine
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D011983	Receptors, Purinergic	Cell surface proteins that bind PURINES with high affinity and trigger intracellular changes which influence the behavior of cells. The best characterized classes of purinergic receptors in mammals are the P1 receptors, which prefer ADENOSINE, and the P2 receptors, which prefer ATP or ADP.	Methyladenine Receptors,Purine Receptors,Purinergic Receptor,Purinergic Receptors,Purinoceptors,Purine Receptor,Purinoceptor,Receptors, Methyladenine,Receptors, Purine,Receptor, Purine,Receptor, Purinergic
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D012995	Solubility	The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Solubilities