Benito-Orfila M A, Domin J, Nandha K A, Bloom S R
Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London, U.K.
Eur J Pharmacol. 1991 Feb 14;193(3):329-33. doi: 10.1016/0014-2999(91)90147-i.
A series of neuromedin U (NmU)-like peptides were found to evoke concentration-response contraction of rat fundic circular muscle in vitro. Isometric contraction of this tissue was induced by rat NmU, porcine NmU-8 and NmU-25, and frog NmU. Rat NmU was significantly more potent than frog NmU. The contractile action of rat NmU upon rat fundic strips was not affected by either atropine or tetrodotoxin indicating a direct effect. Maximal NmU-induced contractions were 10% of the maximal contraction induced by carbachol and ranged between those of the bradykinin and angiotensin II. None of the NmU peptides were active on the circular smooth muscle of the frog stomach or on the small and large intestinal longitudinal smooth muscle of either rat or frog. The results of this study demonstrate that members of the NmU peptide family all induce in vitro contraction of rat gastric circular smooth muscle independent of cholinergic or other neuronal mechanisms. Their activity, however, appears to be both tissue and species specific.
一系列神经介素U（NmU）样肽被发现可在体外引起大鼠胃底环行肌浓度-反应性收缩。该组织的等长收缩由大鼠NmU、猪NmU-8和NmU-25以及青蛙NmU诱导。大鼠NmU的效力明显高于青蛙NmU。大鼠NmU对大鼠胃底条带的收缩作用不受阿托品或河豚毒素的影响，表明其为直接作用。NmU诱导的最大收缩为卡巴胆碱诱导的最大收缩的10%，介于缓激肽和血管紧张素II的收缩作用之间。没有一种NmU肽对青蛙胃的环行平滑肌或大鼠或青蛙的小肠和大肠纵行平滑肌有活性。本研究结果表明，NmU肽家族成员均可在体外诱导大鼠胃环行平滑肌收缩，且不依赖于胆碱能或其他神经元机制。然而，它们的活性似乎具有组织和物种特异性。
