Involvement of cyclooxygenase-dependent pathway in contraction of isolated ileum by urotensin II
Involvement of cyclooxygenase-dependent pathway in contraction of isolated ileum by urotensin II
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DOI：
10.1016/j.peptides.2004.09.009
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发表时间：
2005-02-01
期刊：
影响因子：
3
通讯作者：
Murayama, T
中科院分区：
文献类型：
--
作者：
Horie, S;Tsurumaki, Y;Murayama, T
我们之前报道过尿紧张素II诱导双期（短暂和持久）收缩，这种短暂收缩是由豚鼠回肠段神经节胆碱能神经元释放乙酰胆碱介导的。在目前的工作中，我们研究了由尿紧张素II诱导的持久收缩的机制。0.1 μ m河豚毒素治疗。300 nM ω - concontoxin GVIA（一种n型Ca2+通道抑制剂）和10 nM indomethacin（一种环氧化酶抑制剂）显著抑制100 nM urotensin ii诱导的持久收缩。1 μ m前列腺素F-2alpha （PGF(2alpha)）的加入引起了持续收缩后的有限的短暂收缩。而1mum PGE(2)诱导明显的双相收缩。神经毒素治疗可抑制PGF（2alpha）和PGE(2)诱导的持久收缩，但不改变PGE(2)诱导的短暂收缩。1mum阿托品治疗明显抑制尿紧张素II-和PGF（2alpha）诱导的持久收缩，但对PGE(2)反应的效果较差。用磷脂酶a(2)抑制剂治疗可减少尿紧张素ii引起的收缩。这些发现表明，尿紧张素II通过回肠中pg敏感的胆碱能神经元和毒蕈碱乙酰胆碱受体诱导至少部分持久的收缩。(C) 2004爱思唯尔公司版权所有。
We previously reported that urotensin II induced biphasic (brief- and long-lasting) contractions and the brief contraction was mediated by acetylcholine release from ganglionic cholinergic neurons in a segment of guinea-pig ileum. In present work, we studied the mechanism contributing to long-lasting contractions induced by urotensin II. Treatment with 0.1 muM tetrodotoxin. 300 nM omega-conotoxin GVIA (an inhibitor of N-type Ca2+ channels) and 10 muM indomethacin (an inhibitor of cyclooxygenases) markedly inhibited 100 nM urotensin II-induced long-lasting contractions. The addition of 1 muM prostaglandin F-2alpha (PGF(2alpha)) caused a limited brief contraction following long-lasting, contraction. while 1 muM PGE(2) induced marked biphasic contractions. Treatment with neurotoxins inhibited the long-lasting, contractions induced by PGF(2alpha) and PGE(2) without changing the PGE(2)-induced brief contractions. Treatment with 1 mum atropine markedly inhibited the urotensin II- and PGF(2alpha) -induced long-lasting contractions, but was less effective on the PGE(2) responses. Treatment with a phospholipase A(2) inhibitor decreased the urotensin II-induced contractions. These findings suggest that urotensin II induces at least partiaily long-lasting contractions via PG-sensitive cholinergic neurons and muscarinic acetylcholine receptors in the ileum. (C) 2004 Elsevier Inc. All rights reserved.