试述三磷酸腺苷及其P2X受体在内脏痛机制中的作用

Action of ATP and P2X Receptor in the Visceral Pain Mechanism

三磷酸腺苷(Adenosine triphosphate,ATP)是一种广泛存在于神经系统的神经递质,其P2X受体是一种非选择性阳离子通道,共有P2X1-77个亚型。近年来大量研究表明,P2X受体参与了疼痛的发生与疼痛信号传导,ATP除了通过P2X受体参与疼痛外,还可以通过P2Y1激活PKC参与疼痛机制,后者通过作用于TRPV1而降低质子、辣素和热刺激时TRPV1的激活阈值,这也可能是ATP介导痛敏的另一个机制。由此可以看出,ATP及其P2X受体在内脏痛机制中可能发挥了重要作用。在各内脏器官均可见P2X受体阳性细胞表达,在内脏痛模型中也可见P2X受体表达增高,P2X受体作为一种非选择性阳离子通道,在内脏痛的外周敏化及中枢敏化过程中起到了至关重要的作用。

ATP is a kind of neurotransmitter widely exists in the nervous system;P2X receptor is a kind of non-selective cation channel with P2X1-77 subtypes. Resent researches indicate that the P2X receptor involves in the occurrence of pain and the trans- mission of pain signals. ATP participates in the pain through P2X and involves in the pain mechanism by P2Y1 activating PKC. The latter reduces the activation threshold of proton, capsaicin and TRPVI during heat stimulation,which may be another mecha- nism of ATP conducting pain. It can be seen that ATP and P2X play an important nile in the pain mechanism of the viscera. The expression of P2X receptor positive cells can be seen in every organ, and the enhancement of expression of P2X receptor can also be seen in the visceral pain models. P2X receptor, as a non-selective cation channel,plays a critical role in the peripheral sensiti- zation and central sensitization of visceral pain.