【摘要】 目的　探讨利多卡因治疗耳鸣的神经递质学方面的机制。方法　利用微透析技术和微柱高效液相电化学检测方法研究利多卡因对耳鸣动物模型下丘和颞皮层 5 羟色胺 (5 hydroxytryptamine,5 HT)神经递质的影响。结果　 2 6只白色Wistar大鼠水杨酸钠造模耳鸣 ,显示下丘和颞皮层部位 5 HT的水平显著升高 ,分别在水杨酸钠腹腔注射 2h和 3h升高到基础值的 2 6 8%±2 7% ( x±s,以下同 )和 2 77%± 2 4 % ,通过局部脑组织灌流 ,利多卡因能显著性地降低下丘和颞皮层升高了的 5 HT的水平 ,分别降低至基础值的 85 %± 8%和 92 %± 2 6 %。结论　听觉中枢下丘和颞皮层这两个重要部位 5 HT水平的改变可能与利多卡因抑制耳鸣的机制有关。更多还原

【Abstract】 Objective To elucidate the neurological mechanism of lidocaine′s suppression to tinnitus. Methods Thirty-four Wistar rats weighing 300～350 grams were randomly divided into IC group ( n =17) and AC group ( n =17), according to microdialysis region. Each group was randomly subdivided into saline treatment group ( n =4), salicylate treatment group ( n =6), and salicylate + lidocaine treatment group ( n =7). Using in vivo microdialysis technique coupled with microbore HPLC-electrochemical detection, the present study first monitored the 5-HT release in IC and AC in salicylate-induced tinnitus animal models, and then, examined the effects of lidocaine on salicylate-induced 5-HT changes in IC and AC. The statistical analysis was performed using two-way ANOVA for repeated measures of raw data with time and treatment condition as main effects. Individual time-point values between no more than two groups were compared with the unpaired Student′s t -test. The accepted level of significance was 0.05, two-tailed. Results The 5-HT level increased to a maximum of 268%± 27%( ±s ) basal level in IC 2h after salicylate application and of 277%±24% basal level in AC around 3h after application. And then, the 5-HT level gradually decreased to 157%±16% of baseline in IC and 180%±18% of baseline in AC by the end of the sixth hour. Saline did not alter the IC and AC dialysate 5-HT level in control rats. Two-way ANOVA with repeated measures indicated a significant effect of the condition factor [ F (1,8)=413.949, P <0.000 001 in IC group; F (1,8)=192.184, P <0.000 001 in AC group]. The increases of 5-HT levels in salicylate treatment groups were significantly reduced to 85%±8% basal level in IC and 92%±26% basal level in AC after local infusion of 1% lidocaine ( P <0.05). Compared with corresponding control value at that time (unpaired student t -test). Two-way ANOVA with repeated measures showed a significant difference between the salicylate group and salicylate+lidocaine group [ P <0.000 001 with F (1,11) = 329.267 for the condition factor in IC subgroup; P <0.000 001 with F (1,11) = 133.844 for the condition factor in AC subgroup].Conclusion The suppression of lidocaine to tinnitus may be associated with the decrease of 5-HT level in IC and AC.更多还原