North R A, Surprenant A
Institute of Molecular Physiology, University of Sheffield, United Kingdom.
Annu Rev Pharmacol Toxicol. 2000;40:563-80. doi: 10.1146/annurev.pharmtox.40.1.563.
There are seven P2X receptor cDNAs currently known. Six homomeric (P2X1, P2X2, P2X3, P2X4, P2X5, P2X7) and three heteromeric (P2X2/P2X3, P2X4/P2X6, P2X1/P2X5) P2X receptor channels have been characterized in heterologous expression systems. Homomeric P2X1 and P2X3 receptors are readily distinguishable by their rapid desensitization, the agonist action of alpha beta methyleneATP, and the block by 2',3'-O-(2,4,6-trinitrophenyl)-ATP. P2X2 receptors are unique among homomeric forms in their potentiation by low pH. Homomeric P2X4 receptors are much less sensitive to antagonism by suramin and pyridoxal 5-phosphate-6-azo-2',4'-disulfonic acid. Homomeric P2X7 receptors are the only form in which 2',3'-O-(4-benzoylbenzoyl)-ATP is more potent than ATP. The heteromeric P2X2/P2X3 receptor resembles P2X2 in slow desensitization kinetics and potentiation by low pH and is similar to P2X3 with respect to agonism by alpha beta methyleneATP and block by 2',3'-O-(2,4,6-trinitrophenyl)-ATP. Other agonists, antagonists, and ions that can be used to differentiate among the receptors are discussed.
目前已知有七种P2X受体cDNA。在异源表达系统中已对六种同聚体（P2X1、P2X2、P2X3、P2X4、P2X5、P2X7）和三种异聚体（P2X2/P2X3、P2X4/P2X6、P2X1/P2X5）P2X受体通道进行了表征。同聚体P2X1和P2X3受体可通过其快速脱敏、α,β-亚甲基ATP的激动作用以及2',3'-O-(2,4,6-三硝基苯基)-ATP的阻断作用轻易区分。P2X2受体在同聚体形式中因其对低pH的增强作用而独特。同聚体P2X4受体对苏拉明和磷酸吡哆醛-6-偶氮-2',4'-二磺酸的拮抗作用敏感性低得多。同聚体P2X7受体是唯一一种2',3'-O-(4-苯甲酰苯甲酰)-ATP比ATP更有效的形式。异聚体P2X2/P2X3受体在缓慢脱敏动力学和低pH增强作用方面类似于P2X2，在α,β-亚甲基ATP的激动作用和2',3'-O-(2,4,6-三硝基苯基)-ATP的阻断作用方面与P2X3相似。还讨论了可用于区分这些受体的其他激动剂、拮抗剂和离子。
