Potentiation of pharmacological responses to adenosine, in vitro and in vivo.
1. In washed guinea-pig brain slices, adenosine uptake inhibitors potentiated the responsiveness of cAMP to adenosine, while an adenosine deaminase inhibitor, 2'-deoxycoformycin, was without effect. 2. In the isolated guinea-pig ileum, uptake was important in terminating the inhibitory action of adenosine on nerve-mediated contractions whereas the ADA inhibitor did not affect the ileum or its responses to adenosine in any way. 3. Adenosine given to mice (100 mg/kg i.p.) or guinea-pigs (250 mg/kg i.p.) caused a small, transient fall in body temperature, accompanied by skeletal-muscle relaxation. 4. In mice this temperature fall was potentiated by the uptake blocker dilazep, although only marginally so by the uptake blocker dipyridamole. The ADA-inhibitor also potentiated the pharmacological responses to adenosine. 5. Responses to adenosine in the guinea-pig were less affected by treatment with uptake or ADA-inhibitors, except when given in combination.
D000241:Adenosine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000378:metabolism; D004176:Dipyridamole / Q000494:pharmacology; D004357:Drug Synergism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology
D004176:Dipyridamole; D009538:Nicotine; D000262:Adenylyl Cyclases; D000241:Adenosine