低剂量水杨酸钠大鼠耳鸣模型的建立

Study of tinnitus induced by low dose of sodium salicylate in rats

目的探讨低剂量水杨酸钠诱导耳鸣动物模型。方法 SD大鼠14只,随机分为实验组(条件反射消退期连续2 d腹腔注射120 mg/kg水杨酸钠)和对照组(注射相同剂量生理盐水)。在大鼠形成"声音出现-饮水开始,声音消失-饮水停止"的条件反射后,在条件反射消退期比较实验组和对照组大鼠的饮水抑制率(R)值、饮水量和注射水杨酸钠前后实验组大鼠听性脑干反应(ABR)Ⅲ波的阈值。结果消退期前3 d实验组大鼠R值均较对照组大鼠增高并有显著性差异(F=32.48,P<0.05:F=1 00.6,P<0.05:F=16.06,P<0.05);两组大鼠的饮水量却无统计学差异(P>0.05);实验组大鼠注射水杨酸钠前后ABRⅢ波的阈值并未改变。结论剂量为120 mg/kg的水杨酸钠可以诱导大鼠产生持续3 d的耳鸣。

OBJECTIVE To study the tinnitus animal model induced by low dose of sodium salicylate（SS）. METHODS Fourteen SD rats were randomly divided into treatment group（intraperitoneal injection of 120 mg/ kg SS for 2 consecutive days in conditional testing period） and control group（intraperitoneal injection of the same dose of saline as dose of SS in treatment group）.After all rats have developed a conditioned reflex which associated sound to lick water and silence to stop licking,comparison of suppression ratio（R） between treatment and control groups was studied in conditional testing period.Comparison of weight of drinking water between treatment and control groups and comparison of auditory brainstem response （ABR） before and after SS injection in treatment group were also investigated.RESULTS Statistical analyses showed that R was significantly higher in treatment group than that in control group（P〈0.05） on the former 3 days in conditional testing period,but the weight of drinking water of rats between treatment and control groups showed no significant difference（P〉0.05）.There were no changes in thresholds of III waves of ABR recordings before and 2h after SS treatment.CONCLUSION The dose of 120 mg/kg SS could induce tinnitus which might last 3 days in rats.