倍他司汀对豚鼠单侧迷路破坏后前庭内侧核组胺H3受体表达的影响

Influence of betahistine on the expression of histamine H3 receptor in the medial vestibular nucleus following unilateral labyrinthectomy in guinea pigs

目的 观察倍他司汀（betahistine）对单侧迷路毁损后的豚鼠前庭内侧核（medial vestibular nucleus）组胺H3受体表达的影响.方法 选择听性脑干反应（ABR）阈值小于40 dBSPL的健康黑色赤目纯种豚鼠56只,采用随机数字表法分为3组：假手术组（8只）,单侧迷路破坏组（24只）,单侧迷路破坏＋倍他司汀组（24只）.单侧迷路破坏组和单侧迷路破坏＋倍他司汀组均损毁左侧迷路,假手术组手术打开听泡但保持迷路完好.单侧迷路破坏＋倍他司汀组损毁迷路后给予倍他司汀2.17 mg/kg腹腔注射,每天1次,连续给药至处死当天;另外两组腹腔注射等量生理盐水.破坏单侧迷路的两组在不同观察时间点（术后1、3、7d）各取8只豚鼠通过免疫组织化学染色观察双侧前庭内侧核组胺H3受体的表达变化.采用SPSS 16.0软件对实验数据进行统计分析.结果 单侧迷路破坏组术后1d及3d,受损侧前庭内侧核组胺H3受体表达增加,与假手术组相比,差异具有统计学意义（P＜0.05）,术后7d则恢复至正常水平,与假手术组相比差异无统计学意义（P＞0.05）;未损侧前庭内侧核组胺H3受体表达强度各观察时间点与假手术组相比,差异无统计学意义（P值均＞0.05）.单侧迷路破坏＋倍他司汀组受损侧前庭内侧核组胺H3受体术后1d及3d较同期单侧迷路破坏组表达减弱（4.25 ±0.71、3.50 ±0.92 vs 5.75 ±0.71、5.50 ±0.93,P值均＜0.05）;术后3d、7d与假手术组相比差异无统计学意义（P值均＞0.05）.结论 豚鼠单侧迷路破坏后同侧前庭内侧核中组胺H3受体表达上调,倍他司汀可促进H3受体表达恢复至正常水平.

Objective To observe the influence of betahistine on the expression of histamine H3 receptor in the medial vestibular nucleus （MVN） following unilateral labyrinthectomy （UL）.Methods Fifty-six healthy guinea pigs were randomly divided into three groups：the sham-operated group （group Ⅰ）,the UL group [group Ⅱ,and UL ＋ betahistine （BET） group （group Ⅲ）],BET was intraperitoneally injection at 2.17 mg · kg-1 · d-1 for 7 days.The expression of histamine H3 receptor was analyzed by immunohistochemistry at 1 day,3 days and 7 days after UL.Results H3 receptors were presented in the MVN and the expression of histamine H3 receptor were increased significantly in the ipsilateral MVN at 1 and 3 days after UL（P ＜0.05）,the change turned into the normal value at 7 days（P ＞0.05）.In the UL ＋ BET group,the intensity of histamine H3 receptor was lower than that in the UL at 1 day and 3 days（4.25 ± 0.71,3.50 ± 0.92 vs 5.75 ± 0.71,5.50 ± 0.93,P ＜ 0.05）.However,the changes turned into the normal values at 3 and 7 days （P ＞ 0.05）.Conclusions The early stage of the vestibular compensation process may be associated with the change of H3 receptor expression in MVN.In the UL ＋ BET group the histamine H3 receptor recovered quickly.