POTENT SUPPRESSION OF STRETCH REFLEX ACTIVITY AFTER SYSTEMIC OR SPINAL DELIVERY OF TIZANIDINE IN RATS WITH SPINAL ISCHEMIA -INDUCED CHRONIC SPASTIC PARAPLEGIA

本研究旨在评价替扎尼定（Tizanidine, Tiz）对缺血性痉挛动物拉伸反射活动（SRA）的治疗作用，并确定其作用部位。SRA升高的动物分为几个实验亚组，并进行如下处理：(i) Tiz全身或鞘内（IT）给药；（ii）全身性Tiz治疗后，使用载药或各种肾上腺素能受体（AR）拮抗剂；（iii）用ittizs治疗后，再注射选择性α 2a AR拮抗剂。结果：全身和/或IT治疗Tiz显著抑制SRA。这种tiz介导的抗sra作用可被α 2a AR逆转，但α2B AR拮抗剂无法逆转。脊髓切片免疫荧光染色显示活化星形胶质细胞α2A受体表达上调。

The aim of this study was to evaluate the therapeutic potency of Tizanidine (Tiz) on stretch reflex activity (SRA) in animals with ischemic spasticity, and to delineate sites of Tiz action. Animals with increased SRA were divided into several experimental subgroups and treated as follows: (i) Tiz administered systemically or Intrathecal (IT) delivered; (ii) treatment with systemic Tiz was followed by vehicle, or by various adrenergic receptor(AR) antagonists; (iii) treatment with IT Tizwas followed by the IT injection of selectiveα2A AR antagonist. Results: systemic and/or IT treatment with Tiz significantly suppressed SRA. This Tiz-mediated anti-SRA effect was reversed byα2A AR, but not α2B AR antegonists. Immunofluorescence staining of spinal cord sections showed upregulation of α2A receptor in activated astrocytes.