Liu Jun-xiu, Li Xue-pei, Dong Yu, Han Hui-wan, Liu Guo-quan
Department of Otorhinolaryngology, Peking University Third Hospital, Beijing, 100083, China.
Zhonghua Er Bi Yan Hou Ke Za Zhi. 2003 Dec;38(6):440-4.
To elucidate the neurological mechanism of lidocaine's suppression to tinnitus.
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.
The 5-HT level increased to a maximum of 268% +/- 27% (mean +/- s) basal level in IC 2 h after salicylate application and of 277% +/- 24% basal level in AC around 3 h 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 < 0.000001 in IC group; F(1,8) = 192.184, P < 0.000001 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 < 0.000001 with F(1, 11) = 329.267 for the condition factor in IC subgroup; P < 0.000001 with F(1, 11) = 133.844 for the condition factor in AC subgroup].
The suppression of lidocaine to tinnitus may be associated with the decrease of 5-HT level in IC and AC.
阐明利多卡因抑制耳鸣的神经机制。
将34只体重300 - 350克的Wistar大鼠按微透析区域随机分为IC组（n = 17）和AC组（n = 17）。每组再随机细分为生理盐水治疗组（n = 4）、水杨酸盐治疗组（n = 6）和水杨酸盐 + 利多卡因治疗组（n = 7）。本研究采用体内微透析技术结合微径高效液相色谱 - 电化学检测，首先监测水杨酸盐诱导的耳鸣动物模型中IC和AC区域5 - 羟色胺（5 - HT）的释放，然后检测利多卡因对水杨酸盐诱导的IC和AC区域5 - HT变化的影响。对原始数据进行重复测量的双向方差分析，以时间和治疗条件作为主要效应进行统计分析。不超过两组之间的个体时间点值采用非配对学生t检验进行比较。显著性水平设定为0.05，双侧检验。
应用水杨酸盐后2小时，IC区域5 - HT水平升高至基础水平的268%±27%（平均值±标准差），应用后约3小时，AC区域升高至基础水平的277%±24%。然后，到第6小时结束时，IC区域5 - HT水平逐渐降至基线的157%±16%，AC区域降至基线的180%±18%。生理盐水未改变对照大鼠IC和AC透析液中5 - HT水平。重复测量的双向方差分析表明条件因素有显著影响[IC组中F(1, 8) = 413.949，P < 0.000001；AC组中F(1, 8) = 192.184，P < 0.000001]。局部注入1%利多卡因后，水杨酸盐治疗组中IC区域5 - HT水平的升高显著降低至基础水平的85%±8%，AC区域降至基础水平的92%±26%（P < 0.05）。与当时相应的对照值相比（非配对学生t检验）。重复测量的双向方差分析显示水杨酸盐组和水杨酸盐 + 利多卡因组之间存在显著差异[IC亚组中条件因素F(1, 11) = 329.267，P < 0.000001；AC亚组中条件因素F(1, 11) = 133.844，P < 0.000001]。
利多卡因对耳鸣的抑制作用可能与IC和AC区域5 - HT水平降低有关。
