[关键词]
[摘要]
目的 探讨天麻对小鼠睡眠的促进作用及其对中枢多巴胺(DA)系统的影响,并进一步研究天麻有效成分天麻素通过影响DA通路发挥作用的机制。方法 小鼠随机分为对照组、天麻组、橄榄油组、天麻-橄榄油组及阳性对照艾司唑仑组,每组10只,分别ig给予生理盐水、天麻、橄榄油、天麻-橄榄油和艾司唑仑,连续给药20 d。各组小鼠分别在第7、20天给药30~40 min后ip最大阈下剂量戊巴比妥钠(35 mg/kg),测定睡眠发生率;分别在第8天及第21天ip最小阈上剂量戊巴比妥钠(50 mg/kg),检测小鼠睡眠潜伏期和睡眠时长;采用ELISA法测定天麻对小鼠脑组织DA水平的影响;采用qRT-PCR法检测天麻对DA受体各亚型表达的影响;构建DA受体D1、D2诱导表达稳定细胞株,Western blotting法检测ERK通路相关蛋白的表达水平。结果 与对照组比较,天麻给药20 d后小鼠睡眠潜伏期显著缩短,睡眠发生率提高,睡眠时长延长,中枢DA水平显著提高,DA受体各亚型的表达水平显著上调。同时,天麻中有效成分天麻素可激活DA受体D2而不是D1介导的信号通路。结论 天麻可能通过上调中枢DA系统活性进而调控睡眠,天麻中有效成分天麻素可能通过D2介导的信号通路发挥作用。
[Key word]
[Abstract]
Objective To investigate the sleep promoting effect of Gastrodia elata on mice and its effect on the central dopamine (DA) system, and study the mechanisms of gastrodin, the active constituent of G. elata. Methods Five groups of mice were treated by gavage with saline, gastrodia, olive oil, gastrodia mixed with olive oil and positive control Estazolam, respectively, for 20 d (10 mice per group). Hypnosis induced by suprathreshold and subthreshold doses of Pentobarbital sodium were used to evaluate the effect of G. elata on sleep in mice. Sleep latency, occurrence rate and duration were recorded at the 7th and 20th day. The DA content in the brain tested by ELISA and the expression of DA receptor subtypes detected by qRT-PCR were used to determine the effect of G. elata on central DA system. Western blotting was further used to detect the expression levels of ERK pathway related protein. Results After 20 d of gavage, the sleep latency of mice was significantly shortened, the sleep occurrence rate was increased, the sleep duration was prolonged, and the content of brain DA was significantly increased. At the same time, the expression levels of all the dopamine receptor subtypes were significantly up-regulated. Furthermore, the gastrodin, the active constituent of G. elata, could activate the dopamine receptor D2 rather than the D1-mediated signaling pathway. Conclusion G. elata might regulate sleep by up-regulating the activity of central DA system. Gastrodin, the active constituent of G. elata, could play a regulating role through D2-mediated signaling pathway.
[中图分类号]
[基金项目]
国家自然科学基金资助项目(81460417);国家自然科学基金资助项目(81473342)