title: A novel non-adrenergic, non-cholinergic nerve-mediated relaxation of the pig bladder neck: an examination of possible neurotransmitter candidates.
abstract: Electrical field stimulation of the isolated pig bladder neck preparation initiated rapid non-adrenergic, non-cholinergic nerve-mediated relaxations. A wide range of substances were examined as possible candidates for the neurotransmitter involved. Of these, only 5-hydroxytryptamine, vasoactive intestinal polypeptide, adenosine and adenosine 5'-triphosphate produced relaxations. Noradrenaline, acetylcholine, substance P, bradykinin and angiotensin II caused contraction, while neurotensin, somatostatin, bombesin and gamma-amino butyric acid were without effect. The nerve response was not blocked by methysergide, ketanserin, chymotrypsin, apamin or 8-phenyltheophylline, although methysergide antagonised the responses to 5-hydroxytryptamine, chymotrypsin blocked the responses to VIP, and 8-phenyltheophylline antagonised the responses to adenosine and ATP.
mesh_terms: D000241:Adenosine / Q000502:physiology; D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects; D018377:Neurotransmitter Agents / Q000502:physiology*; D012701:Serotonin / Q000502:physiology; D013552:Swine; D001743:Urinary Bladder / Q000187:drug effects / Q000294:innervation*; D014660:Vasoactive Intestinal Peptide / Q000502:physiology
chemical_list: D018377:Neurotransmitter Agents; D012701:Serotonin; D014660:Vasoactive Intestinal Peptide; D000255:Adenosine Triphosphate; D000241:Adenosine