Beta-endorphinergic neurons in nucleus arcuatus and nucleus tractus solitarii mediated depressor-bradycardia effect of "Tinggong" 2Hz-electroacupuncture.
The central neural mechanisms underlying the depressor-bradycardia effect of the "Tinggong" 2Hz-electroacupuncture (EA-DpB) were analyzed: (1) Brain transection caudal to nucleus arcuatus (AR) or procaine preinjection into bilateral AR could block the EA-DpB; (2) preinjection of naloxone into bilateral nucleus paraventricularis could even reverse the EA-DpB, but beta-endorphin antiserum had no significant effect on the EA-DpB; (3) after procaine injection into the nucleus commissuraris (the caudal part of NTS), the EA-DpB was also blocked; (4) preinjection of naloxone or beta-endorphin antiserum into bilateral rostral ventrolateral medulla (RVL) attenuated or reversed the EA-DpB response, taken together with our previous findings that the RVL mediates the depressor response to the excitation of the beta-endorphinergic neurons in AR or NTS, the above results suggest that the EA-DpB is mediated by the beta-endorphinergic projections from the AR and NTS to RVL. Finally the mechanism underlying the reverse of the EA-DpB by naloxone injection into nucleus paraventricularis was discussed.
Ku
Y H
YH
Department of Physiology, Beijing Medical University, P. R. China.
Zou
C J
CJ
D015669:Acupuncture Points; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000187:drug effects / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D001919:Bradycardia / Q000503:physiopathology*; D015671:Electroacupuncture; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D008297:Male; D008526:Medulla Oblongata / Q000187:drug effects / Q000502:physiology; D009270:Naloxone / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011343:Procaine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017552:Solitary Nucleus / Q000187:drug effects / Q000502:physiology*; D001615:beta-Endorphin / Q000037:antagonists & inhibitors / Q000502:physiology*
D009270:Naloxone; D011343:Procaine; D001615:beta-Endorphin