力竭运动对大鼠大脑P2X_2、P2X_4和P2X_6受体表达的影响

Effect of Exhaustive Exercise on the Expression of Brain P2X_2,P2X_4,and P2X_6 Receptors in Rats

目的:探讨一次和反复力竭游泳运动后大鼠大脑ATP受体P2X之三个亚型P2X2、P2X4和P2X6的时相性变化特点。方法:健康成年雄性SD大鼠68只,分为一次力竭游泳运动组和反复力竭游泳运动组及安静对照组,反复力竭组大鼠每日负重3%体重进行力竭游泳运动,共训练2周。运动组分别于力竭运动后即刻、4小时、12小时和24小时取材,采用实时荧光定量PCR方法测定力竭运动后大鼠P2X2、P2X4和P2X6受体亚型mRNA水平。结果:(1)反复力竭运动后12小时组P2X2相对表达率达到峰值,与反复力竭其它各组及安静对照组、一次力竭12小时组均有显著差异(P<0.01)。(2)一次力竭即刻组P2X4相对表达率与安静对照组、4小时组、12小时组比较有显著统计学差异(分别为P<0.01、P<0.05、P<0.01)。(3)反复力竭运动后12小时组P2X6相对表达率达到峰值。结论:3种受体亚型在一次力竭运动和反复力竭运动后12小时出现峰值或峰值趋势,提示在力竭运动后12小时,这3种P2X受体亚型所参与的中枢神经生理生化活动在此时可能会达到一个活跃期。

Objective The main purpose of this study is to investigate the variation in P2XE,P2X4 and P2X6 receptors in rats brain at different time points after single bout exhaustive exercise and repeated exhaustive exercise. Methods Sixty-eight male SD rats were divided randomly into the single＇ bout exhaustive swimming group （SE）, repeated exhausting swimming （RE）, and sedentary group （C）. The rats in group RE with weight-bearing 3% of body weight swan to exhaustion each day for a total of two weeks. The brain tissue of the rats was removed at 0 hr,4 hr, 12 hr and 24 hr after the last exhaustive swimming. The mRNA levels of P2X2,P2X4 and P2X6 receptors in the brain tissue were observed through real-time quantitative PCR method. Results （1）The peak relative expression rate of the P2X2 in the group RE revealed at 12 hr after exhaustive swimming,which was significantly different from that at the other time points in the same group,and from the group C （P 〈 0.01 ）,and at 12 hr after the single bout exhaustive exercise（P 〈 0.01 ）. （2）The relative expression rate of P2X4 at 0 hr in the group RE was significantly higher than that at 4 hr and 12 hr in group SE and group C （P 〈 0.01 ,P 〈 0.05 ,P 〈 0.01 ,respectively）.（3）The peak expression rate of P2Xs was seen at 12 hr in group RE,and was statistically different from that at 24 hr in the same group（P 〈 0.05）. Conclusion After both the single bout and repeated exhaustive exercises, the relative expression rate of the 3 receptor subtypes reached or trended to reach its peak at 12 hr, suggesting that the activity of 3 P2X receptor subtypes involved in the physiological and biochemical activities in the central nervous system at that time point.