title: Arylazido aminopropionyl ATP (ANAPP3): interaction with adenosine receptors in longitudinal smooth muscle of the guinea-pig ileum.
abstract: Arylazido aminopropionyl ATP (ANAPP3), an ATP-receptor antagonist containing a photosensitive arylazido moiety coupled to the 3' hydroxyl of ATP, inhibited the twitch response of electrically stimulated ileal longitudinal muscle strips in a dose-dependent manner. These agonist responses to ANAPP3 were attenuated by the enzyme adenosine deaminase and antagonized by the adenosine receptor antagonist 8-phenyltheophylline. Schild analysis yielded similar pA2 values for ANAPP3 and adenosine suggesting a common receptor site. Several 3'-ribose-modified adenosine analogs were tested for agonist activity and found to be inactive. Results suggest that ANAPP3 interacts at the presynaptic adenosine receptor of the ileum following its metabolism to adenosine, which explains the lack of antagonism at adenosine receptors of ileal smooth muscle following photolysis of ANAPP3.
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000243:Adenosine Deaminase / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001386:Azides / Q000494:pharmacology*; D004558:Electric Stimulation; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D011983:Receptors, Purinergic; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: C012761:3'-O-(3-(N-(4-azido-2-nitrophenyl)amino)propionyl)adenosine-5'-triphosphate; D001386:Azides; D011956:Receptors, Cell Surface; D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate; D013806:Theophylline; C028322:8-phenyltheophylline; D000243:Adenosine Deaminase; D000241:Adenosine