title: Phylogenetic distribution of [3H]cyclohexyladenosine binding sites in nervous tissue.
abstract: The specific binding of the A1 adenosine receptor ligand, [3H]CHA, was investigated in membrane fractions prepared from brains of eleven vertebrate species and ganglia of four invertebrate species. Substantial amounts of specific [3H]CHA binding sites were demonstrated in brain membranes of all vertebrate species examined; however, [3H]CHA binding sites were not detectable in nervous tissue of the invertebrate species studied. The densities of [3H]CHA binding sites in vertebrate brains increase in higher vertebrates. Moreover, the pharmacological characteristics of the site labeled by [3H]CHA in two divergent classes of vertebrates were similar. The broad phylogenetic distribution of A1 adenosine receptors in primitive as well as advanced vertebrate species suggests a fundamental role for adenosine in neuronal modulation.
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000378:metabolism; D000663:Amphibians / Q000378:metabolism; D000818:Animals; D001181:Arthropods / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D002645:Chickens / Q000378:metabolism; D005399:Fishes / Q000378:metabolism; D006168:Guinea Pigs; D008566:Membranes / Q000378:metabolism; D051379:Mice; D008974:Mollusca / Q000378:metabolism; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011983:Receptors, Purinergic; D013045:Species Specificity; D014714:Vertebrates / Q000378:metabolism
chemical_list: D011956:Receptors, Cell Surface; D011983:Receptors, Purinergic; C027513:N(6)-cyclohexyladenosine; D000241:Adenosine