Effects Of Electroacupuncture At Tinggong And Yifeng On Glucose Metabolism And IGF-1Expression In Auditory Cortex Of Guinea Pigs

Objective: To investigate the effects and mechanisms of electroacupuncture atTinggong and Yifeng on the local expression of insulin like growth factor(IGF-1) and glucose metabolism in the auditory cortex of guinea pig.Methods:1. Groups and model building. There were18adult pigmented guinea pigswith no history of ototoxic drug use, noise exposure and normal auricle reflex.These guinea pigs were randomly divided into3groups by the random numbertable method, which included electroacupuncture at auricular points group(EAPG, n=7), electroacupuncture at non acupoint group (ENAG, n=6) andcontrol group (CG, n=5). Guinea pigs in EAPG were electroacupunctured atTinggong and Yifeng acupoints simultaneously for15minutes every day, andelectroacupunctur lasted7days. The ENAG were electroacupunctured at nonacupoints for the same time. The CG received no treatment.2. Changes inglucose metabolism in the auditory cortex. After anesthetized, guinea pigswere injected18F-FDG via dorsocuboidal vein, and scanned by PET/CT. PETimage and CT image were processed and reconstructed in the workstation toobserve the uptake of imaging agent in the brain of guinea pigs. The maximumSUV values and its ratios between auditory cortex and cerebellum were measured.3. Expressions of IGF-1mRNA in auditory cortex tissues. Theexpression of IGF-1mRNA were detected by real-time fluorescencequantitative PCR.4. Statistical Methods. The results were analysed bythe one-way ANOVA using SPSS17.0software, and P<0.05means statisticalsignificance.Results:1. Changes in glucose energy metabolism in theauditory cortex. The ratios of the maximum SUV value between auditorycortex and cerebellum were0.75±0.06,0.84±0.05and0.71±0.06respectively for CG, EAPG and ENAG. There was a significant differencebetween the CG and EAPG (P<0.05), the EAPG and ENAG (P<0.05), and nosignificant difference between the CG and ENAG (P>0.05).2、Changes inlocal expression of IGF-1mRNA in the auditory cortex. The fold changesin IGF-1mRNA were1.34±0.24，2.03±0.36and0.92±0.23respectively forCG, EAPG and ENAG. There was a significant increase in IGF-1mRNAexpression in auditory cortex of the EAPG (P<0.05, compared with the CGand ENAG), and a significant difference between the EAPG and ENAG(P<0.05).Conclusion:1.Acupuncturing at Tinggong and Yifeng point canimprove glucose metabolism in the auditory center of guinea pig.2.Acupuncturing at Tinggong and Yifeng point can result in increase of the localexpression of IGF-1in the auditory center of guinea pig.3. Local IGF-1mayplay a role in the increase of the glucose metabolism of the auditory center after acupuncturing at Tinggong and Yifeng of guinea pig.