EFFECTS OF 5-HYDROXYTRYPTAMINE ON DISCHARGE OF VAGAL MUCOSAL AFFERENT-FIBERS FROM THE UPPER GASTROINTESTINAL-TRACT OF THE FERRET
EFFECTS OF 5-HYDROXYTRYPTAMINE ON DISCHARGE OF VAGAL MUCOSAL AFFERENT-FIBERS FROM THE UPPER GASTROINTESTINAL-TRACT OF THE FERRET
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DOI：
10.1016/0165-1838(93)90360-7
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发表时间：
1993-10-01
期刊：
影响因子：
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通讯作者：
GRUNDY, D
中科院分区：
文献类型：
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作者：
BLACKSHAW, LA;GRUNDY, D
本研究旨在确定5-羟色胺（5-HT）对迷走神经粘膜传入末梢的影响，以及这可能与它们对其他刺激的敏感性有关。记录了乌拉坦麻醉雪貂颈部迷走神经的上消化道粘膜中具有感受野的单一传入纤维。选择标准包括对管腔扩张无反应（即，排除迷走神经张力受体）。所有测试的纤维都对粘膜抚摸有反应。其中大多数（28/32）对动脉内近距离应用5-HT（10 μ g）也有反应，出现短暂的动作电位爆发（通常< 15 s），其中6/6例被5-HT 3受体拮抗剂格拉司琼（0.1-0.5 mg/kg i. v.）减少或消除，对八肽胆囊收缩素（100-400 pmol，接近I.A.）也有四种反应。在6种情况下，在2-75 μ g的剂量范围内，对5-HT的反应显示出剂量依赖性。腔刺激，其中包括150 mM盐酸，1 M氯化钠，和粘膜中风，没有被格拉司琼阻断，虽然在三个纤维，静息放电被拮抗剂减少，这表明迷走神经粘膜传入静息放电可能受到内源性释放的5-HT的影响。
This study was undertaken to determine the effects of 5-hydroxytryptamine (5-HT) on vagal mucosal afferent endings and how this may relate to their sensitivity to other stimuli. Single afferent fibres with receptive fields in the mucosa of the upper gastrointestinal tract were recorded from the cervical vagus of Urethane anaesthetized ferrets. The selection criteria included failure to respond to luminal distension (i.e., vagal tension receptors were excluded). All fibres tested responded to mucosal stroking. The majority of these (28/32) also responded to close-intrarterially applied 5-HT (10 mug) with a brief burst (usually < 15 s) of action potentials, which in 6/6 cases was reduced or abolished by the 5-HT3 receptor antagonist granisetron (0.1-0.5 mg/kg i.v.), as were four responses to cholecystokinin-octapeptide (100-400 pmol close I.A.). The response to 5-HT was shown to be dose-dependent over the dose range 2-75 mug on six occasions. Responses to luminal stimuli, which included 150 mM HCl, 1 M NaCl, and mucosal stroking, were not blocked by granisetron although in three fibres, the resting discharge was reduced by the antagonist, suggesting that resting discharge in vagal mucosal afferents may be influenced by endogenously released 5-HT.