Biomaterial Database

Effects of enprofylline on A1 and A2 adenosine receptors. 1985

D Ukena, and C G Schirren, and U Schwabe

The effects of enprofylline were studied on A1 adenosine receptors of rat fat cells and on A2 adenosine receptors of human platelets and of guinea-pig lung. Enprofylline antagonized the 5'-N-ethylcarboxamidoadenosine (NECA)-induced stimulation of platelet adenylate cyclase activity with a KB of 130 microM. In human platelets, enprofylline did not antagonize but potentiated the NECA-induced inhibition of aggregation. This potentiation was abolished in the presence of the phosphodiesterase inhibitor papaverine. An adenosine antagonistic effect of enprofylline could not be evaluated on A2 receptors of guinea-pig lung because the xanthine enhanced basal and NECA-stimulated cyclic AMP accumulation. Enprofylline antagonized the N6-R-(-)-phenylisopropyladenosine (R-PIA)-induced inhibition of rat fat cell adenylate cyclase with a KB of 32 microM. The Ki value for inhibition of [3H]PIA binding to fat cell membranes was 45 microM. Enprofylline inhibited cyclic AMP phosphodiesterase activity of human platelets, guinea-pig lung and rat fat cells with Ki values of 15, 130 and 110 microM, respectively. The results show that enprofylline was nearly equipotent as antagonist at A1 and A2 adenosine receptors. Mechanisms other than adenosine antagonism or phosphodiesterase inhibition may be involved in the pharmacological effects of enprofylline.

UI	MeSH Term	Description	Entries
D008168	Lung	Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.	Lungs
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
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
D001792	Blood Platelets	Non-nucleated disk-shaped cells formed in the megakaryocyte and found in the blood of all mammals. They are mainly involved in blood coagulation.	Platelets,Thrombocytes,Blood Platelet,Platelet,Platelet, Blood,Platelets, Blood,Thrombocyte
D001993	Bronchodilator Agents	Agents that cause an increase in the expansion of a bronchus or bronchial tubes.	Bronchial-Dilating Agents,Bronchodilator,Bronchodilator Agent,Broncholytic Agent,Bronchodilator Effect,Bronchodilator Effects,Bronchodilators,Broncholytic Agents,Broncholytic Effect,Broncholytic Effects,Agent, Bronchodilator,Agent, Broncholytic,Agents, Bronchial-Dilating,Agents, Bronchodilator,Agents, Broncholytic,Bronchial Dilating Agents,Effect, Bronchodilator,Effect, Broncholytic,Effects, Bronchodilator,Effects, Broncholytic
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000242	Cyclic AMP	An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.	Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine