尾加压素Ⅱ (urotensinⅡ ,UⅡ )最早是从硬骨鱼的尾部下垂体中分离出来的生长抑素样结构的环形神经肽[1] 。近年陆续发现UⅡ广泛存在于从软体动物到哺乳动物的神经系统中 ,能引起多种动物的离体和在体动脉血管收缩 ,其强度是内皮素的十余倍 ,是迄今所知的最强的缩血管神经肽[2 UrotensinⅡ (UⅡ) is the earliest ring-shaped neuropeptide of somatostatin-like structure isolated from the tail pituitary of teleost fish. In recent years, it has been found that UⅡ is widely present in the nervous system from molluscs to mammals and can cause ex vivo and in vivo arterial vasoconstriction in a variety of animals. Its intensity is more than ten times that of endothelin and is by far the strongest known Of vasoconstrictor neuropeptides [2