基于TRPV1和P2X3交互作用的大鼠外周痛感觉调控机制

Regulation mechanism of peripheral pain sensation in rats based on the interaction between TRPV1 and P2X3

目的 观察大鼠外周TRPV1和P2X3的相互关系,以期部分阐明外周痛感觉调控机制。方法雄性SD大鼠随机分为空白对照组、TRPV1激动剂组、P2X3激动剂组、TRPV1激动剂+P2X3激动剂组、TPRV1激动剂+P2X3抑制剂组、P2X3激动剂+TRPV1抑制剂组。通过足底皮下注射TRPV1或P2X3激动剂和(或)抑制剂,分别观察20min内各组大鼠缩足次数、抬腿/舔足持续时间;采用免疫荧光法观察L4DRG水平TRPV1和P2X3阳性面积表达及共表达情况;采用免疫共沉淀法观察L4DRG水平TRPV1和P2X3的相互关系。结果 P2X3激动剂不能提升TRPV1激动剂诱发的痛行为学,P2X3抑制剂能减轻TRPV1激动剂诱发的痛行为学;TRPV1激动剂能增加P2X3激动剂诱发的痛行为学,TRPV1抑制剂不会减轻P2X3激动剂诱发的痛行为。P2X3激动剂能增加L4DRG水平TRPV1阳性面积表达,TRPV1激动剂能增加L4DRG水平P2X3阳性面积表达;TRPV1和P2X3在DRG水平有共表达且存在共沉淀现象。结论 外周神经元水平,TRPV1和P2X3之间存在一定的相互作用。两者可以相互促进对方的表达。当其中一方受到抑制时,另一方的功能也会相应的降低。

Objective To assess the relationship between peripheral TRPV1 and P2X3 in normal healthy rats to elucidate the regulation mechanism of peripheral pain sensation.Methods Healthy male SD rats were randomly divided into a control group,TRPV1 agonist group,P2X3 agonist group,TRPV1 agonist+P2X3 agonist group,TPRV1 agonist+P2X3 inhibitor group,and P2X3 agonist+TRPV1 inhibitor group.Within 20 min after subcutaneous and intraplantar injections of TRPV1 or P2X3 agonist and/or inhibitor,the number of foot contractions and the duration of leg raising/licking in each group were measured,respectively.The expression and co-expression of positive cells of L4DRG TRPV1 and P2X3 were observed using immunofluorescence.The correlation between TRPV1 and P2X3 at L4 DRG levels was observed using immunoprecipitation.Results The P2X3 agonist did not alleviate pain behavior induced by the TRPV1 agonist,and the P2X3 inhibitor did.The TRPV1 agonist increased pain behavior induced by P2X3 agonist,and the TRPV1 inhibitor did not reduce pain behavior induced by P2X3 agonist.The P2X3 agonist increased the positive area expression of TRPV1 in at the L4DRG level,and the TRPV1 agonist increased the positive area expression of P2X3 at the L4DRG level;TRPV1 and P2X3 were co-expressed and co-precipitated at the L4 DRG level.Conclusions There is an interaction between TRPV1 and P2X3 at the peripheral neuron level,whereby they promote each other’s expression.When one is inhibited,the other is reduced in function.