Rioux F, Kérouac R, St-Pierre S
Life Sci. 1984 Jul 23;35(4):423-31. doi: 10.1016/0024-3205(84)90653-2.
Neurotensin (NT) evoked a transient, dose-dependent histamine release (ED50 170 ng ml-1) from the rat perfused heart. Histamine release by NT occurred within seconds and lasted less than 2 min. The histamine releasing effect of NT was followed by a dose-dependent increase of the perfusion pressure and a slight tachycardia. The histamine releasing effect of NT was completely abolished in hearts derived from rats pretreated for 3 days with high doses of compound 48/80. The coronary vasoconstrictor effect of NT was increased in hearts derived from compound 48/80-pretreated rats. The mast cell inhibitor cromoglycate markedly inhibited NT-induced histamine release without affecting the coronary vasoconstrictor effect of NT. The histamine releasing effect of NT was inhibited, while its coronary vasoconstrictor effect was markedly potentiated, in hearts derived from rats pretreated with the antiallergic and antiinflammatory steroid dexamethasone. The increase of perfusion pressure evoked by NT was not modified by antihistamine drugs. Infusions of exogenous histamine (10(-6)-10(-5) g ml-1) caused a dose-dependent coronary vasodilation in the rat perfused heart. The results suggest that NT stimulates histamine release from cardiac mast cells. These results together with those obtained in previous studies suggest that mast cell mediators (particularly histamine and serotonin) are unlikely to be responsible for the coronary vasoconstrictor effect of NT in the rat perfused heart.
神经降压素（NT）可引起大鼠离体灌流心脏组胺的瞬时、剂量依赖性释放（半数有效剂量为170 ng/ml）。NT引起的组胺释放在数秒内发生，持续时间不到2分钟。NT释放组胺后，灌注压呈剂量依赖性升高，心率略有加快。用高剂量化合物48/80预处理大鼠3天，其心脏中NT释放组胺的作用完全消失。在化合物48/80预处理大鼠的心脏中，NT的冠状动脉收缩作用增强。肥大细胞抑制剂色甘酸显著抑制NT诱导的组胺释放，而不影响NT的冠状动脉收缩作用。在用抗过敏和抗炎类固醇地塞米松预处理大鼠的心脏中，NT释放组胺的作用受到抑制，而其冠状动脉收缩作用则明显增强。NT引起的灌注压升高不受抗组胺药物的影响。在大鼠离体灌流心脏中，输注外源性组胺（10⁻⁶ - 10⁻⁵ g/ml）可引起剂量依赖性冠状动脉舒张。结果表明，NT刺激心脏肥大细胞释放组胺。这些结果与先前研究结果共同表明，肥大细胞介质（特别是组胺和5-羟色胺）不太可能是NT在大鼠离体灌流心脏中引起冠状动脉收缩作用的原因。
