Chung O, Csikós T, Unger T
Institute of Pharmacology, Christian-Albrechts-University, Kiel, Germany.
J Hum Hypertens. 1999 Jan;13 Suppl 1:S11-20; discussion S33-4. doi: 10.1038/sj.jhh.1000744.
Angiotensin II (Ang II) has diverse physiological actions leading, for example, to increases in extracellular volume, peripheral vascular resistance and blood pressure, and has also been implicated in the regulation of cell growth and differentiation. Molecular cloning and pharmacological studies have defined two major classes of Ang II receptors, designated as AT1 and AT2. Most effects of Ang II are mediated by AT1 receptors. Much less is known about the physiological role of AT2 receptors. Recent evidence suggests involvement of AT2 receptors in development, cell differentiation, apoptosis and regeneration in various tissues. AT1 and AT2 receptors have been shown to exert counteracting effects on cellular growth and differentiation, vascular tone and the release of arginine vasopressin (AVP). In each condition the AT2 receptor appears to down-modulate actions mediated by the AT1 receptor, resulting in decreased cellular proliferation, decreased levels of serum AVP levels or decreased vasoconstrictor responses. In addition, in neuronal cell lines, the AT2 receptor reportedly exerts antiproliferative effects and promotes neurite outgrowth, an effect accompanied by significant changes in the gene expression pattern of growth- and differentiation-related genes.
血管紧张素II（Ang II）具有多种生理作用，例如可导致细胞外液量增加、外周血管阻力增加和血压升高，并且还与细胞生长和分化的调节有关。分子克隆和药理学研究已确定了两大类血管紧张素II受体，分别命名为AT1和AT2。血管紧张素II的大多数作用是由AT1受体介导的。对于AT2受体的生理作用了解得要少得多。最近的证据表明，AT2受体参与了各种组织的发育、细胞分化、细胞凋亡和再生过程。已表明AT1和AT2受体对细胞生长和分化、血管张力以及精氨酸加压素（AVP）的释放具有拮抗作用。在每种情况下，AT2受体似乎都会下调由AT1受体介导的作用，从而导致细胞增殖减少、血清AVP水平降低或血管收缩反应减弱。此外，据报道，在神经元细胞系中，AT2受体具有抗增殖作用并促进神经突生长，这一作用伴随着生长和分化相关基因的基因表达模式发生显著变化。
