Effect of Liyan Tongqiao Fang on tongue muscle contraction in rats after hypoglossal nerve injury.

Objective To discuss the therapeutic effect of Liyan Tongqiao Fang (Soothing-throat Freeing-orifice Formula) on tongue muscle contraction in rats after hypoglossal nerve injury by applying nerve-muscle electrophysiology method. Methods Male adult Wistar rats (n = 60) were randomly divided into sham-operation group, model group and Liyan Tongqiao Fang group (each n = 20). The model of hypoglossal nerve injury was established by clamping in model group and Liyan Tongqiao Fang group, while in sham-operation group hypoglossal nerve was only separated without champing. After modeling for 2 d, Liyan Tongqiao Fang group was given Liyan Tongqiao Fang (0. 3 mg/d), and sham- operation group and model group were given the same quantity of saline solution. The threshold strength, single contraction amplitude and tonic contraction amplitude were detected in all groups respectively on the 7th d and the 14th d. Results The threshold intensity of injured tongue muscle increased in model group compared with sham-operation group (P < 0. 05) at the same time point, and decreased in Liyan Tongqiao Fang group compared with model group (P < 0. 05) at the same time point. The threshold intensity of injured tongue muscle increased in model group and Liyan Tongqiao Fang group compared with non-injured tongue muscle within the same group (P < 0. 05). The threshold intensity of injured tongue muscle decreased in Liycin Tongqiao Fang group and model group on the 14th d compared with that on the 7th d (P < 0. 05). The single contraction amplitude and tonic contraction amplitude of injured tongue muscle decreased in model group compared with sham-operation group (P <0. 01) at the same time point, and increased in Liyan Tongqiao Fang group compared with model group (P < 0. 05) at the same time point. The single contraction amplitude and tonic contraction amplitude of injured tongue muscle decreased in model group and Liyan Tongqiao Fang group compared with non-injured tongue muscle within the same group (P < 0. 05). The single contraction amplitude and tonic contraction amplitude of injured tongue muscle increased in Liyan Tongqiao Fang group and model group on the 14th d compared with those on the 7th d (P < 0. 05). Conclusion Liyan Tongqiao Fang can reduce the contraction threshold intensity, promote excitability of hypoglossal nerve-tongue muscle conduction system, improve the contraction ability of tongue muscle, and relieve dysphagia in rats after hypoglossal nerve injury. [ABSTRACT FROM AUTHOR]