Effects Of Electroacupuncture At Tinggong And Yifeng On MDA Expression In Auditory Center Of Guinea Pigs With Age-related Hearing Loss By D-galactose

Objective:Age-related hearing loss (AHL) is a degenerative disease, which severely affects the physical and mental health of the old people. Because of the long course and bad curative effect of AHL, the early intervention to the AHL research is necessary. Acupuncture has the early characteristic of early intervention, and should play an important role in the prevention and treatment of AHL.The purpose of the study is to establish a model of guinea pigs with AHL by subcutaneous injection of D-galactose, and investigate the effects of MDA on the mechanism of AHL and the changes in the expression of MDA in auditory cortex, inferior colliculus and cochlear nucleus of guinea pigs with AHL after electroacupuncture at Tinggong and Yifeng. Methods:There were 4 groups.30 adult guinea pigs were randomly divided into 3 groups including the D-galactose group (DQ n=10), the D-galactose and electroacupuncture group (DEG, n=10), and control group (CG, n=10). The fourth group was the elderly group (n=10). Guinea pigs of the DG and DEG groups were subcutaneously injected D-galactose (300mg/kg.day) for 6 weeks, and the DEG was electroacupunctured at Tinggong and Yifeng at the same time. The CG was subcutaneously injected the same dose of physiological saline. After 6 weeks, ABR were tested, and MDA expression in auditory cortex, inferior colliculus and cochlear nucleus of guinea pigs was quantitated by the TBA method. Results:(1) There were some aging symptoms including severe depilation, loss of appetite, and decrease of the auricle reflex in the DG. Compared with the CG, the weight decreased in the DG (P<0.05). (2) The average latent period of the third wave of ABR was 0.89±0.88,1.06±0.14,0.90±0.10,1.00±0.10 ms. There was a significant increase in the latent period of the third wave of the DG (P<0.05,compared with CG), and a significant decrease in the DEG (P<0.05,compared with DG). (3) There was an increase in MDA express of the auditory cortex, inferior colliculus and cochlear nucleus of the DG and elderly group (P< 0.05, compared with CG), a decrease in the 3 regions of the DEG (P< 0.05, compared with DG), and no significant difference in the 3 regions of the DG (P>0.05, compared with elderly group). Conclusions:(1) It is an effective way to establish a guinea pig model with AHL by subcutaneous injection of D-galactose (300mg/kg.day) for 6 weeks. (2) D-galactose can result in the aging of the auditory center of the guinea pig. (3) The aging of the auditory center would be related with the increase in the ability of lipid peroxidation induced by the increase of MDA content. (4) It is effective to electroacupuncture at Tinggong and Yifeng for partly inhibiting the aging process of the auditory center.