围绝经期抑郁大鼠肠道微生物菌群的研究

Study on intestinal microflora in rats with peri-menopausal depression

目的研究围绝经期抑郁大鼠肠道微生物菌群的变化,为防治围绝经期抑郁提供实验室依据。方法20只雌性SD大鼠均双侧卵巢切除去势进行围绝经期造模,然后随机分为2组,每组各10只。实验组采用慢性不可预见性温和应激(CUMS)刺激4周诱导抑郁模型,对照组未进行CUMS刺激。刺激前、刺激后1、2、3和4周分别测量两组大鼠体重,通过糖水偏好实验、强迫游泳实验和旷场实验检测抑郁行为的变化;抑郁造模成功后处死两组大鼠,提取结肠粪便细菌DNA,采用变性梯度凝胶电泳(DGGE)检测肠道微生物菌群的变化,对指纹图谱进行组间菌群多样性与相似性分析。结果与对照组相比较,实验组自应激刺激第2周起体重显著减轻(均P<0.05);应激刺激4周后糖水消耗率和旷场中央区域活动距离显著下降(均P<0.05),游泳悬浮不动时间显著增加(P<0.05);DGGE检测、非加权配对算术平均法(UPGMA)聚类分析结果提示肠道菌群多样性显著减少,组内相似性显著下降(P<0.01),组间相似系数仅为(54.84±11.07)。结论围绝经期抑郁大鼠的肠道菌群紊乱,多样性降低。

Objective:To study the alteration of intestinal microflora in rats with peri-menopausal depression,and provide laboratory basis for the prevention and treatment of peri-menopausal depression.Methods:Twenty female Sprague-Dawley(SD)rats were all ovariectomized for establishing peri-menopausal model,and then the rats were randomly divided into two groups,each with 10 rats.The rats in experimental group were induced by chronic unpredictable mild stress(CUMS)for depression,while the rats in control group had no CUMS stimulation.The body weight of the two groups were measured before and 1,2,3 and 4 weeks after stimulation.The depression behavior changes were assessed by using the sucrose preference test(SPT),forced swimming test(FST)and open field test(OFT).The rats of two groups were sacrificed after successful establishment of depression model,and total DNA of intestinal microflora was extracted from the feces of colon.Denaturing gradient gel electrophoresis(DGGE)was used to detect the changes of intestinal microflora,and the fingerprints were analyzed for the diversity and similarity of the flora between groups.Results:Compared with the control group,the weight of the rats in experiment group significantly decreased since the second week of CUMS stimulation(all P<0.05).After four weeks of CUMS stimulation,the sucrose water consumption rate and the active distance in the central area of the open field in the experiment group were significantly reduced(all P<0.05),but the immobility time in forced swimming was significantly increased(P<0.05).The results of DGGE detection and unweighted paired arithmetic average(UPGMA)cluster analysis showed that the diversity of intestinal flora was significantly reduced,the similarity within the group was significantly decreased(P<0.01),and the similarity coefficient between groups was only(54.84±11.07).Conclusions:The intestinal flora of peri-menopausal depression rats is disordered and its diversity is reduced.