延迟性雷美替胺处理对脑冷冻伤后神经功能和组织修复的调节作用  

Effects of delayed ramelteon treatment on neurological function and tissue repair after cryogenic traumatic brain injury

作　　者：李宇 杜原鑫 陈茹 马文磊 王维则 范彦英[1] LI Yu;DU Yuan-xin;CHEN Ru;MA Wen-lei;WANG Wei-ze;FAN Yan-ying(Dept of Pharmacology,Shanxi Medical University,Taiyuan 030001,China)

机构地区：[1]山西医科大学基础医学院药理教研室,山西太原030001

出　　处：《中国药理学通报》2023年第2期325-331,共7页Chinese Pharmacological Bulletin

基　　金：国家自然科学基金资助项目(No 81872854)。

摘　　要：目的研究在脑冷冻伤(cryogenic traumatic brain injury,cTBI)亚急性期连续每日给予雷美替胺对小鼠神经功能障碍和脑组织修复的调节作用。方法将30只雄性C57BL/6小鼠随机分为对照组、损伤组和雷美替胺处理组。将经液氮预冷的铜棒按压颅骨,以造成右侧感觉运动皮层损伤。以cTBI后不同时间点(1 h、1 d、3 d)为起始给药时间,连续每日灌胃给予雷美替胺(10 mg·kg^(-1)·d^(-1)),并在14 d后取材。采用平衡木实验、旷场实验来评价小鼠运动功能;采用甲苯胺蓝染色来检测脑梗死体积;利用免疫荧光检测脑梗死周边区GAP-43和synaptophysin的表达;利用Iba-1检测小胶质细胞激活;通过检测GFAP阳性区域,分析胶质疤痕的面积和厚度。结果3种给药时程的雷美替胺处理(1 h~14 d,1~14 d和3~14 d)均可明显改善cTBI导致的小鼠运动功能障碍并减小脑梗死体积,可促进GAP-43和synaptophysin表达,并减少胶质疤痕面积和厚度以及激活态的小胶质细胞数量。此外,各药物处理组对上述指标的作用程度相当。结论延迟性雷美替胺处理可改善cTBI后神经功能障碍,且有效给药时间窗可延迟至cTBI后3 d,该作用可能与抑制胶质疤痕形成和小胶质细胞激活,促进轴突再生、突触发生有关。Aim To study the effects of continuous daily administration of ramelteon starting at the subacute period of cryogenic traumatic brain injury(cTBI)on neurological function and brain tissue repair in mice.Methods Thirty male C57BL/6 mice were randomly divided into sham group,vehicle group and ramelteon treatment groups.The right sensory-motor cortex was damaged by pressing a copper probe precooled by liquid nitrogen onto the skull.Ramelteon(10 mg·kg^(-1)·d^(-1))was administered by gavage every day starting at different time points after cTBI(1 h,1 d,3 d)until sacrifice on day 14.Beam walking test and open field test were used to evaluate the motor function.Toluidine blue staining was used to measure the infarct volume.Immunofluorescence was used to detect the expression of GAP-43 and synaptophysin in peri-infarct area.Microglia activation was detected using Iba-1.The area and thickness of glial scars were analyzed by detecting GFAP positive areas.Results All three treatment(1 h-14 d,1-14 d,and 3-14 d)significantly improved cTBI induced motor dysfunction,reduced the infarct volume,elevated the expression of GAP-43 and synaptophysin,and decreased the area and thickness of glial scar and microglia activation.In addition,all ramelteon treatment groups had similar effects on the above indexes.Conclusions Delayed ramelteon treatment can improve neurological dysfunction after cTBI,and the therapeutic time window can be delayed for up to three days after cTBI.Inhibiting glial scar formation and microglia activation,and promoting axonal regeneration and synaptogenesis may contribute to the beneficial effects of ramelteon.

关 键 词：脑冷冻伤 雷美替胺 轴突再生 突触发生 小胶质细胞 胶质疤痕 

分 类 号：R-332[医药卫生] R322.81R645R651.15R916.4