On the purinergic system in rat duodenum: existence of P1 and P2 receptors on the smooth muscle.
In rat duodenum, in vitro, in the presence of atropine and guanethidine, ATP administration caused a tetrodotoxin-insensitive relaxation followed by a rebound contraction. A similar response was obtained also after electrical field stimulation (EFS) of non-adrenergic, non-cholinergic (NANC) nerves. alpha, beta-methylene-TP and theophylline antagonized the response to ATP, but they failed to affect the noradrenaline- and EFS-induced relaxation. These results suggest that P1 and P2 receptors are present in rat duodenum, but their activation is not responsible for the inhibitor effects due to the NANC nerves.
Dipartimento di Biologia celluare e dello Sviluppo, Università di Palermo.
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D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D004386:Duodenum / Q000187:drug effects / Q000294:innervation*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000294:innervation / Q000502:physiology; D051381:Rats; D011983:Receptors, Purinergic / Q000187:drug effects / Q000502:physiology*; D013806:Theophylline / Q000494:pharmacology
D011983:Receptors, Purinergic; D000255:Adenosine Triphosphate; D013806:Theophylline