Local Cationic Channels-mediated Analgesic Effect And Mechanism Of Acupuncture And Moxibustion

Objective: To clarify the analgesic effect of electroacupuncture and moxibustion on acid-and purine-induced pain;to explain the role of local cationic channels ASIC3,TRPV1,P2X3,P2X7 in electroacupuncture and moxibustion analgesia.Methods: Injecting with acidic PBS(pH 6.0 or 4.0)or purine substance(?.?-me ATP or Bz-ATP)on the left hind paw of Sprague Dawley(SD)rats to induce acute pain;performing electroacupuncture or moxibustion at "Zusanli"(ST36)for 30 minutes and measuring the PWL to estimate the analgesic effect of electroacupuncture and moxibustion on acid-and purine-induced pain;combining with the selective antagonist of ASIC3,TRPV1,P2X3,P2X7,as well as TRPV1-KO mice and P2X7-KO mice,to clarify the role of local cationic channels ASIC3,TRPV1,P2X3,P2X7 in electroacupuncture and moxibustion analgesia;injecting with CFA to induce inflammatory pain,and applying the selective antagonist of ASIC3,TRPV1,P2X3,P2X7 respectively or simultaneously to clarify the electroacupuncture and moxibustion analgesia in inflammatory pain;all the results were analyzed by Graphpad 8.0.Results:(1)Electroacupuncture and moxibustion efficaciously reversed the decrease of PWL induced by injection with pH6.0,pH4.0,?.?-me ATP(200n M)or Bz-ATP(50n M)in rats(P <0.05).(2)APET(20?M),Ugr9-1(20?M)and Amiloride(10?M)reversed the decrease of PWL caused by pH6.0 and ?.?-me ATP(200n M)(P<0.05).(3)Capsazepine(10?M)reversed the PWL decline caused by pH6.0 and pH4.0(P<0.05);electroacupuncture and moxibustion efficaciously reversed the decrease of PWL in pH6.0-induced pain in wild-type mice and TRPV1-KO mice(P<0.05).(4)A-317491(300n M)reversed ?.?-me ATP but not pH6.0 or Bz-ATP induced PWL decrease.(5)A-438079(300n M)reversed the decrease of PWL caused by Bz-ATP(50n M)(P<0.05);plantar injection with Bz-ATP caused PWL decrease in wild-type mice but not in P2X7-KO mice.(6)The decline of PWL caused by CFA was reversed by electroacupuncture rather than moxibustion;application of APET combined with A317491,A317491 combined with A438079 as well as Capsazepine combined with A317491 reversed CFA induced PWL decrease.Conclusions:(1)Electroacupuncture and moxibustion relieve acid-and purine-induced pain;(2)The local cationic channels ASIC3 may mediate electroacupuncture and moxibustion analgesia on acid-and purine-induced pain;electroacupuncture and moxibustion relieve purine-induced pain via mediating local cationic channels P2X3 and P2X7.(3)The local cationic channels ASIC3,TRPV1,P2X3 and P2X7 may mediated electroacupuncture attenuate CFA-induced inflammatory pain.