| Objective:To investigate the time sequence of energy metabolism in auditory cortex(AC) of guinea pig following chronic kanamycin-induced deafness, and the effects and mechanisms of electroacupuncture at auricular points on the plasticity of auditory cortex of guinea pig following chronic kanamycin-induced deafness. Methods: 1. Animal groups. 105 adult guinea pigs were randomly divided into three groups, including control group(CG), kanamycin treatment group(KTG), and kanamycin sulfate + electroacupuncture at auricular points group(EG). Guinea pigs were treated with saline in control group, and kanamycin sulfate by subcutaneous injection at 500 mg/kg per day for 7 days in KTG and EG. Moreover, guinea pigs were electroacupunctured at Yifeng and Tinggong acupoints for 7 days in EG after half an hour of kanamycin treatment. Depending on the time of observation, KTG and EG were divided into 7 groups, including 1, 7, 14, 28, 56, 70 and 140 days groups. 2. Energy metabolism was detected by PET/CT in auditory cortex. Guinea pigs were injected with 18F- fluorodeoxyglucose imaging agent(18F-FDG) at 2mic/kg by foot dorsal vein, and scanned by PET/CT at 50 minutes after treatment. The uptake rate of 18F-FDG was analyzed andobserved in the auditory cortex of guinea pigs by sketching the area of interest of bilateral auditory cortex and cerebellum in the same level. The auditory cortex and cerebellum maximum standard uptake value(SUV) were measured by the computer. 3. Determination of the activity of lactate dehydrogenase(LDH)and succinate dehydrogenase(SDH)of auditory cortex tissues. The activity of LDH and SDH of auditory cortex tissues was detected in guinea pigs by the method of enzyme chemical. Statistical methods: Data are expressed by x ± s, and the statistical software is SPSS17.0. The results were analyzed by ANOVA, and SNK was selected to analyze the differences between two groups. Results: 1. The changes of glucose metabolism of auditory cortex. The average ratios of maximum SUV between AC and cerebellum were 0.73 ± 0.04, 0.72 ± 0.04, 0.72 ± 0.07, 0.72 ± 0.03, 0.75 ± 0.05, 0.70 ± 0.04, 0.78 ± 0.08 and 0.84 ± 0.04, respectively in CG and at 1, 7, 14, 28, 56, 70 and 140 days after kanamycin treatment, and 0.74 ± 0.02, 0.69 ± 0.09, 0.77 ± 0.04, 0.83 ± 0.02, 0.81 ± 0.06, 0.76 ± 0.02 and 0.83 ± 0.03 respectively at 1, 7, 14, 28, 56, 70 and 140 days in EG. The effects of kanamycin on the glucose metabolism of auditory cortex were analyzed by ANOVA(F(7,40)=4.671, P<0.005). The effects of electroacupuncture on the glucose metabolism of auditory cortex following chronic kanamycin-induced deafness were analyzed(F(13,70)=5.852, P<0.001). The ratios of maximum SUV between AC and cerebellum increased in KTG at140 days(P<0.05, compared with the CG) and EG at 28 and 56 days(P<0.05, compared with the KTG). 2. The changes in theactivity of LDH of auditory cortex tissues. The average activity of LDH were 24.23 ± 2.97, 52.61 ± 8.55, 27.22 ± 4.65, 35.67 ± 7.54, 56.73 ± 11.84, 25.18±2.01, 24.19 ± 3.03 and 29.71 ± 4.37 U/mgprot respectively in CG and at 1, 7, 14, 28, 56, 70 and 140 days after kanamycin treatment in KTG, and 23.08 ± 2.23, 23.20 ± 1.54, 25.47 ± 6.49, 31.87 ± 5.02, 18.14 ± 1.17, 20.79 ± 1.33 and 25.26 ± 7.20 U/mgprot respectively at 1, 7, 14, 28, 56, 70 and 140 days in EG. The effects of kanamycin on the activity of LDH of auditory cortex were analyzed by ANOVA(F(7, 24) =16.459, P<0.001). The effects of electroacupuncture on the activity of LDH of auditory cortex following chronic kanamycin-induced deafness were analyzed(F(13,42)=16.035, P<0.001). The activity of LDH increased in KTG at 1, 14 and 28 days(P<0.05, compared with the CG), and the activity of LDH decreased in EG at 1, 14 and 28 days(P<0.05, compared with the KTG). 3. The changes in the activity of SDH of auditory cortex tissues. The activity of SDH were 231.99±24.18, 261.42±43.37, 177.48±37.07, 256.54±8.76, 179.80±72.28, 236.51±65.68, 270.81±1.20 and 235.65±33.27 U/mgprot respectively in CG and at 1, 7, 14, 28, 56, 70 and 140 days after kanamycin treatment in KTG, and 225.55±7.99, 315.42±51.29, 409.05±41.10, 320.86±11.27, 390.47±98.13, 246.88±30.41 and 236.96±86.82 U/mgprot respectively at 1, 7, 14, 28, 56, 70 and 140 days in EG. The effects of kanamycin on the activity of SDH of auditory cortex were analyzed by ANOVA(F(7, 24) =2.371, P<0.05). The effects of electroacupuncture on the activity of SDH of auditory cortex following chronic kanamycin-induced deafness were analyzed(F(13,42)=7.222, P<0.001). Therewere no statistically significant differences in the activity of SDH of KTG(P>0.05,compared with the CG), and the activity of SDH increased in EG at 7, 14, 28 and 56 days(P<0.05, compared with the KTG). Conclusions: 1. The glucose metabolism of auditory cortex of guinea pigs is of plasticity following chronic kanamycin-induced deafness. 2. Electroacupuncture at auricular points may improve glucose metabolism of auditory cortex following chronic kanamycin-induced deafness. 3. Electroacupuncture at auricular points may reduce anaerobic glycolysis and enhance aerobic metabolism by decreasing the activity of lactate dehydrogenase and increasing the activity of succinate dehydrogenase of auditory cortex following chronic kanamycin-induced deafness. |
PDF Full Text Request