作者: Karl M Jenkinson , Julianne J Reid
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摘要: In the rat gastric fundus, non-adrenergic, non-cholinergic (NANC) relaxations are mediated by nitric oxide (NO), vasoactive intestinal polypeptide (VIP), and a third, as yet unidentified, neurotransmitter. The possible involvement of adenosine 5′-triphosphate (ATP) in NANC was examined using pyridoxalphosphate-6-azophenyl-2′,5′-disulphonic acid (PPADS), apamin desensitization to α,β-methylene ATP. responses were studied absence presence NG-nitro-L-arginine methyl ester (NAME; 100 μM) α-chymotrypsin (1 u ml−1), inhibit NO VIP, respectively. PPADS (100 μM), (1 μM) ATP (10 μM, three additions) all significantly (P<0.05) reduced electrical field stimulation (0.5–4 Hz, 30 s trains) longitudinal strips fundus almost abolished residual relaxation remaining NAME α-chymotrypsin. PPADS had no effect on NO-donor, sodium nitroprusside (SNP), or VIP. Apamin slightly SNP, but did not affect those whereas markedly both SNP VIP. The effects PPADS this study provide strong evidence that third inhibitory neurotransmitter is ATP. British Journal Pharmacology (2000) 130, 1627–1631; doi:10.1038/sj.bjp.0703481