内皮素受体的分布及其生物功能

内皮素（Endothelin, ET）是一种由21个氨基酸组成的生物活性物质。它主要由内皮细胞合成，具有非常强烈的收缩血管的生物活性。近年来研究发现除了具有强烈缩血管作用，同时内皮素也具有诱导血管生成、促分化、促细胞有丝分裂和类细胞生长因子的性质。研究文献发现人有3种内皮素亚型（ET-1、ET-2、ET-3），这三个异构肽的生物活性有一定差异，ET-1的作用最强，ET-3最弱。内皮素分子通过内皮素受体（ETRs）发挥其生理和病理作用。内皮素受体被发现广泛地表达于动物的心血管系统、神经系统和胃肠道之中。内皮素受体A（ETA）和内皮素受体B（ETB）有共同的信号转导通路。同时，ETB激活后还能促进PLA2激活。研究还发现内皮素与良恶性肿瘤有广泛的联系。

Distribution and biological function of endothelin receptors

Endothelins （ETs） are composed of 21-aminoacids produced by endothelial cells and considered to be potent vasoconstrictor. Recent studies found that they could not only induce the angiogenesis, mitosis and differentiation, but also act the role of cytokines. Previous studies have identiifed three isoforms of ET （ET-1, ET-2 and ET-3）, which are involved in a variety of physiological and pathological processes. ET-1 is most potent one among ETs, whereas ET-3 is the weakest once. ET peptides exhibit their functions in a number of mammalian physiological systems, including gastrointestinal. ETs act via two distinct isoforms of receptors in human body, i.e. endothelin receptor A （ETA） and endothelin receptor B （ETB）, which can be found expressed in many mammalian cardiovascular system, neural system and gastrointestinal tract. ETA and ETB have same signaling pathways. And at the meantime, ETB can promote the activation of PLA2. The study also found that endothelins were widely associated with benign and malignant diseases.