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

Abstract

To observe the influence of betahistine on the expression of histamine H3 receptor in the medial vestibular nucleus (MVN) following unilateral labyrinthectomy (UL). 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. 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). 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.