Objective:

2

To investigate the effects of electroacupuncture (EA) on endolymphatic hydrops (EH) and the regulation of arginine vasopressin (AVP)-aquaporin-2 (AQP2) pathway in guinea pigs.

Methods:

2

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 10 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) and AQP2 mRNA expressions in the cochlea were compared among groups.

Results:

2

EA significantly reduced cochlear hydrops in guinea pigs (

P

=0.001). EA significantly attenuated the AVPinduced 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 (

P

=0.004) in the cochlea.

Conclusion:

2

The dehydrating effect of EA might be associated with its inhibition of AVP-AQP2 pathway activation.