Effects Of Electroacupuncture At Tinggong And Yifeng On SOD Expression In Cochlear Nucleus, Inferior Colliculus And Auditory Cortex Of Guinea Pigs With Age-related Hearing Loss

Objective: To establish a guinea pig model with aged-related hearing loss(AHL) by D-galactose, and investigate the effects and mechanism ofelectroacupuncture at ear acupoint on age-related hearing loss. Methods:There were four groups.30mixed colored adult guinea pigs (weigh300~550g) were divided into3groups randomly and the elderly groupincluded102-years-old guinea pigs (weigh600~900g). After raised forone week, guinea pigs in the D-galactose group (DG) weresubcutaneously injected D-galactose （300mg/kg.day）, equal physiologi-cal saline in the control group (CG), and D-galactose （300mg/kg.day）and electroacupunctured at Tinggong and Yifeng in the D-galactose andelectroacupuncture group (DEG) for six weeks. The elderly group (EG)were raised and observed in a low noise environment. After6weeks,ABR were tested, and the auditory cortex tissues were fixed in4%paraformaldehyde (PH=7.2-7.6) quickly for morphological study. Theslices were stained by HE and neurons were analyzed. The tissuesincluding auditory cortex, inferior colliculus and cochlear nucleus in eachgroup were obtained, the protein content was measured using theCoomassie Brilliant Blue, and SOD expression was investigated using the Spectrophotometer. The data were analyzed by SPSS13.0software andthe method of the statistics was analysis of variance. Results:1.Therewere some aging symptoms, such as gradually hearing loss, loss ofappetite and depilation in the DG, DEG and elderly group.2.The averageABR threshold was39.00±7.38,79.44±6.62,70.00±5.88and81.88±4.43dB SPL respectively in the CG, DG, DEG and elderly group. Therewas a significant increase in ABR threshold of the DG, DEG and theelderly group (P＜0.001, compared with CG), and a decrease in DEG (P＜0.001, compared with DG).3.The activity of the SOD decreased in thecochlear nucleus, inferior colliculus and auditory cortex of the DG andelderly group (P＜0.01, compared with CG), and increased in the3regions of the DEG (P＜0.01, compared with DG). Conclusions:1.It isan effective method to establish a guinea pig model with AHL bysubcutaneously injecting D-galactose （300mg/kg.day）for6weeks.2.D-galactose can result in aging of the auditory center of the guinea pig.3. The aging of the auditory center would be related with the decrease inthe ability of anti-oxidant induced by the decline of the SOD activity.4. Itis effective to electroacupuncture at Tinggong and Yifeng for partlyinhibiting the aging process.