Kérouac R, St-Pierre S, Rioux F
Life Sci. 1984 Mar 5;34(10):947-59. doi: 10.1016/0024-3205(84)90299-6.
Neurotensin (NT) (1 X 10(-8) - 1.5 X 10(-6) g ml-1) caused a transient, dose-dependent increase in perfusion pressure in the rat perfused hindquarter. The vasoconstrictor effect of NT was associated with a short-lived, dose-dependent release of histamine and 5-hydroxytryptamine (5-HT) in the hindquarter effluent. Compound 48/80, a classical mast cell secretagogue, also elicited a vasoconstrictor effect in, and release of histamine from, the rat hindquarter. The vasoconstrictor effect and the release of histamine and 5-HT evoked by NT were much smaller in hindquarters derived from rats pretreated with compound 48/80 for 4 days to cause mast cell depletion than in hindquarters derived from control rats. The mast cell inhibitor cromoglycate (4 mg ml-1) inhibited by about 50% the histamine releasing effect and vasoconstriction produced by the lowest concentrations of NT utilized. The histamine releasing effect of compound 48/80 was more sensitive to blockade by cromoglycate than that of NT. The steroidal antiinflammatory and antiallergic drug dexamethasone did not affect the histamine and 5-HT releasing effect of NT. The vasoconstrictor effects of NT, compound 48/80 and 5-HT were markedly reduced by the 5-HT receptor antagonist methysergide (1 X 10(-7) g ml-1). Histamine (1 X 10(-6) - 10(-4) g ml-1) evoked a decrease in perfusion pressure in hindquarters pre-exposed to noradrenaline. The results suggest the participation of mast cell 5-HT in the vasoconstrictor effect of NT in the rat perfused hindquarter.
神经降压素（NT）（1×10⁻⁸ - 1.5×10⁻⁶ g/ml）可使灌注的大鼠后肢灌注压出现短暂的、剂量依赖性升高。NT的血管收缩作用与后肢流出液中组胺和5-羟色胺（5-HT）的短暂、剂量依赖性释放有关。经典的肥大细胞促分泌剂化合物48/80也能在大鼠后肢引发血管收缩作用并促使组胺释放。在用化合物48/80预处理4天导致肥大细胞耗竭的大鼠的后肢中，NT诱发的血管收缩作用以及组胺和5-HT的释放比对照大鼠后肢中的要小得多。肥大细胞抑制剂色甘酸（4 mg/ml）可抑制所用最低浓度NT产生的组胺释放效应和血管收缩作用约50%。化合物48/80的组胺释放效应比NT的组胺释放效应更易被色甘酸阻断。甾体抗炎抗过敏药物地塞米松不影响NT的组胺和5-HT释放效应。5-HT受体拮抗剂麦角新碱（1×10⁻⁷ g/ml）可显著降低NT、化合物48/80和5-HT的血管收缩作用。组胺（1×10⁻⁶ - 10⁻⁴ g/ml）可使预先暴露于去甲肾上腺素的后肢灌注压降低。结果表明肥大细胞5-HT参与了灌注的大鼠后肢中NT的血管收缩作用。
