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 up-regulated 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