JIANG Liyuan, HE Jiaojun, CHEN Xixi, SUN Xuejiao, WANG Xuezhong, ZHONG Shan, CHEN Huade 

(The Third Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou 310053, China)

Abstract:  Objective:  The  objective  of  this  study  was  to  investigate  the  effects  of electroacupuncture  (EA)  on  endolymphatic  hydrops  (EH)  and  the  regulation  of  Arginine vasopressin-aquaporin-2  (AVP-AQP2)  pathway  in  guinea  pigs,  so  as  to  explore  the  possible mechanism of EA. Methods：  EH was induced in male guinea pigs by an intraperitoneal injection of  AVP.  For  the  treatment,  EA  was  delivered  to  “Baihui”  (GV  20)  and “Tinggong”  (SI  19) acupoints, once per day for ten consecutive days. In histomorphological studies, cochlear hydrops degree was evaluated by hematoxylin-eosin (HE) staining, and then the ratio of scala media (SM) area  to  SM  +  scala  vestibuli  (SV)  area  (R  value)  was  calculated.  In  mechanical  studies,  a comparison  of  plasma AVP  (p-AVP)  concentrations,  cyclic  adenosine  monophosphate (cAMP) levels, vasopressin type 2 receptor (V2R) mRNA and AQP2 mRNA expression in the cochlea was made  among  groups.  Results：EA  significantly  reduced  cochlear  hydrops  in  guinea  pigs (P=0.001). EA significantly attenuated the AVP-induced up-regulation of p-AVP concentrations (P=0.006),  cochlear  cAMP  levels  (P=0.003)  and AQP2  mRNA  expression  (P=0.016),  and  upregulated the expression of V2R mRNA in the cochlea (P=0.004).  Conclusion：These results suggest  that  dehydrating  effect  of  EA  might  be  associated  with  its  inhibition  of  AVP-AQP2 pathway activation. 

Key words: endolymphatic hydrops,electroacupuncture,  AVP-AQP2 pathway, Meniere’s disease