[Theophylline-induced changes in the presynaptic effects of adenosine, baclofen, clofelin and morphine in the myenteric plexus of the guinea pig].
The experiments on the isolated guinea-pig ileum have shown that the contractions caused by low frequency transmural stimulation are decreased by adenosine, baclofen, clofelin and morphine. Theophylline is a competing antagonist of adenosine and a noncompeting antagonist of baclofen, clofelin and morphine. The effects of the latter are not altered by 1,3-dipropyl-8-phenylxanthine suppressing adenosine effects. It is concluded that presynaptic effects of baclofen, clofelin and morphine depend on cAMP level in cholinergic neurons of myenteric plexus.
D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D004347:Drug Interactions; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D009197:Myenteric Plexus / Q000187:drug effects*; D011950:Receptors, Cholinergic / Q000187:drug effects; D017981:Receptors, Neurotransmitter / Q000187:drug effects*; D013806:Theophylline / Q000494:pharmacology*
D011950:Receptors, Cholinergic; D017981:Receptors, Neurotransmitter; D009020:Morphine; D013806:Theophylline; D001418:Baclofen; D000241:Adenosine; D003000:Clonidine
Izmenenie teofillinom presinapticheskikh éffektov adenozina, baklofena, klofelina i morfina v mienteral'nom spletenii kishki morskikh svinok.