糖尿病大鼠颈性前庭诱发肌源性电位的观察

Cervical Vestibular Evoked Myogenic Potential in Diabetes Rats

目的观察糖尿病大鼠不同时期的颈性前庭诱发肌源性电位(cervical vestibular evoked myogenic potential,cVEMP)的变化及意义。方法将220只雄性SD大鼠随机分为对照组(20只)及糖尿病组(200只),应用链脲佐菌素(streptozotocin,STZ)诱导糖尿病大鼠模型,再按照造模的时间将糖尿病组分为糖尿病4、6、8、10、12周组,每组40只,观察各组大鼠的一般情况及血糖、ABR、cVEMP检测结果。结果糖尿病组大鼠造模后出现多饮、多食、多尿等典型糖尿病症状,与对照组比较,血糖升高(P<0.01)、体重下降(P<0.01);糖尿病组从第6周开始出现ABR反应阈值升高(P<0.05);糖尿病组cVEMP阈值第8周(53.87±11.16dB nHL)、第10周(67.00±12.74dB nHL)、第12周(67.00±9.23dB nHL)升高(P<0.01),P1波潜伏期第8周(5.01±0.33ms)、第10周(5.37±0.45ms)、第12周(5.39±0.24ms)延长(P<0.01),N1波潜伏期第10周(8.98±0.86ms)、第12周(9.08±0.45ms)延长(P<0.01),但糖尿病组P1-N1波间振幅与对照组比较差异无统计学意义(P>0.05)。结论糖尿病大鼠从造模成功第8周开始,cVEMP阈值开始升高、P1波及N1波潜伏期延长,出现不同程度的前庭终器损伤,提示cVEMP可作为早期诊断前庭功能损害的方法之一。

Objective To verify whether cervical vestibular evoked myogenic potential （cVEMP） can be used as an effective method to assess vestibular functions in diabetic rats, we examined and analyzed cervical vestibular evoked myogenic potential （cVEMP） in different duration diabetic rats and normal rats. Methods A total of 220 male SD rats were randomly divided into control group （n= 20） and diabetes group （n= 200）. The diabetic rats were further divided into 4,6,8,10, and 12 week groups （40 rats each group） according to the diabetes duration. Diabetes was induced by STZ. The general situation,ABR and cVEMP were conducted in all the groups. Results All diabetic groups appeared typical diabetic symptoms including polydipsia, polyuria, more food, weight loss （P〈 0.01） and blood glucose elevation （P〈0.01）. The threshold of ABR was significantly elevated （P〈0.05） in the 6, 8,10, and 12 week diabetic group. Compared to the normal group, the threshold of cVEMP was significantly elevated in 8 week（53.87±11.16 dB nHL）,10 week（67.00±12.74 dB nHL）,12 week（67.00±9.23 dB nHL） diabetes groups（P〈0.01） and the mean latency of P1 peak was significantly prolonged （P〈0.01） in 8 week（5.01±0.33 ms） ,10 week（5.37±0.45 ms） ,and 12 week（5.39±0.24 ms） . The mean latency of N1 peak was significantly prolonged （P〈0.01） in 10 week （8.98±0.86 ms）, and 12 week （9. 084-0.45 ms） compared to the control group. As to P1 - N1 amplitudes, there was no significantly difference among all groups （P〉 0. 05）. Conclusion In the cVEMP test , the threshold increased, the PI peak latency and N1 peak latency prolonged from the 8 th week of diabetes rats models. Vestibular functions were descent gradually due to different degrees of vestibular end--organ impairment.All data indicated that VEMP could be used as an early diagnostic method.