酸枣仁汤对失眠大鼠中脑中缝背核神经胶质细胞的影响

Effect of Suanzaoren Decoction on the Glia Cell in the Dorsal Raphe Nuclei of Insomnia Rats

目的:研究酸枣仁汤对失眠大鼠中脑中缝背核星形胶质细胞和小胶质细胞的作用。方法:采用连续2 d ip对氯苯丙氨酸(PCPA)350 mg.kg-1的方法建立失眠大鼠模型。动物随机分为空白对照组,模型组,酸枣仁汤治疗组和西药对照组。酸枣仁汤治疗组按15,7.5,3.75 g.kg-1ig 7 d,西药对照组按2 mg.kg-1给予艾司唑仑2 mg.kg-1ig 7 d。取脑组织,用HE染色观察中脑中缝背核区神经细胞损伤情况,采用免疫组织化学染色法对中脑胶质原纤维酸性蛋白(GFAP)和小胶质细胞OX42进行染色,观察与睡眠和觉醒密切相关的中脑中缝背核GFAP和OX42表达的变化。结果:PCPA失眠模型组神经损伤评分与空白对照组相比具有显著性差异(P<0.01),PCPA失眠模型组大鼠中脑中缝背核GFAP与OX42表达增强,阳性细胞数增多,与空白对照组相比,差异具有统计学意义(P<0.01);酸枣仁汤高剂量组(15 g.kg-1)GFAP与OX42表达与模型组相比具有显著性差异(P<0.01),酸枣仁汤高剂量组GFAP与OX42表达与西药对照组相比无显著性差异。结论:PCPA所致失眠能导致大鼠中脑中缝背核组织损伤,PCPA所致失眠能激活大鼠中脑中缝背核星形胶质细胞和小胶质细胞,酸枣仁汤能减少失眠大鼠中脑中缝背核星形胶质细胞和小胶质细胞的激活,改善神经细胞损伤程度,这可能是酸枣仁汤治疗失眠症的作用环节之一。

Objective： To explore the effect of Suanzaoren decoction （SZRD） on the expression of astrocytes and microglia cells in the dorsal raphe nuclei （DRN） insomnia rats. Method： The insomnia rat model was established by intraperitoneal injection of DL-4-Chlorophenylalanine （PCPA） at the dose of 350 mg·kg^（-1） for two days. Rats were divided into control group, model group, SZRD groups, and estazolam group. The SZRD groups were treated by intragastric administration of SZRD at 15, 7.5, 3.75 g ·kg^（-1） each day for seven days. The estazolam group was treated the same way using estazolam at 2 mg .kg-1 for 7 days. HE staining was use to check the neural damage in the DRN and test animal＇ s midbrain glial fibrillary acidic protein （GFAP） ; and OX42 expression was examined using immunohistochemical staining. Result： The level of neural damage in the DRN was significantly higher in the insomnia model group than in the control group （P 〈 0.01 ）. Insomnia model group rats showed significantly higher levels （P 〈 0.01 ） of GFAP and OX42 positive cells in the DRN than control animals. Treatment animals receiving a high dose of SZRD （15 g -kg-1） showed significantly lower levels （P 〈 0.01 ） of GFAP and OX42 positive cells in the DRN than insomnia model group animals. This treatment group showed no significant difference when compared to animals treated using estazolam. Conclusion： PCPA can damage the DRN neurons. Insomnia induced by PCPA can activate midbrain astrocytes and microglia. SZRD reduces midbrain GFAP and oxg2 expression, and reduces the damage from PCPA. This may be one of the mechanisms for SZRD in treatment of insomnia.