多囊卵巢综合征合并慢性应激状态大鼠模型的建立及评价

目的建立贴近临床的多囊卵巢综合征(PCOS)合并慢性应激状态动物模型,探讨不良心理应激对PCOS的影响,为进一步研究提供实验基础。方法选取6周龄SPF级SD雌性大鼠32只,采用随机数字表法将大鼠分为空白组、慢性应激组(CUMS)、多囊卵巢综合征组(PCOS)、多囊卵巢综合征合并慢性应激组(PCOS+CUMS),每组各8只。空白组大鼠正常饮水进食,CUMS组大鼠以慢性温和不可预知应激(CUMS)方法模拟慢性心理应激,PCOS组采用来曲唑灌胃构建大鼠模型,PCOS+CUMS组大鼠在给予来曲唑的同时,应用CUMS方法建立PCOS合并慢性应激状态大鼠模型,连续造模28 d。观察各组大鼠体质量变化;采用旷场实验、蔗糖偏嗜实验评价大鼠行为学情况;采用苏木精-伊红染色观察大鼠卵巢组织形态学变化;采用酶联免疫吸附法(ELISA)测定血清黄体生成素(LH)、卵泡刺激素(FSH)、游离睾酮(FT)水平,并计算LH/FSH比值;采用高效液相色谱-电化学法(HPLC-ECD)测定海马组织中5-羟色胺(5-HT)及其代谢产物5-羟吲哚乙酸(5-HIAA)水平。结果造模后,PCOS组、PCOS+CUMS组大鼠体质量、血清FT水平、LH/FSH比值均高于空白组,差异具有统计学意义(P<0.05);PCOS组大鼠卵巢内可见多个囊性扩张卵泡,而PCOS+CUMS组卵巢组织多囊样改变更加明显;CUMS组、PCOS+CUMS组大鼠水平运动得分、垂直运动得分、蔗糖偏嗜度及海马组织中5-HT含量均低于空白组,5-HIAA含量高于空白组,差异均具有统计学意义(P<0.05)。结论PCOS与不良心理应激之间相互影响,可使疾病进展;来曲唑联合CUMS诱导的PCOS合并慢性应激状态动物模型,其卵巢病理改变、内分泌紊乱及行为学变化等方面与临床特征更接近,可作为研究PCOS合并心理应激的病理及药效学机制的可靠动物模型。

Establishment and evaluation of the rat model of polycystic ovary syndrome with chronic stress

Objective To establish a clinical model of polycystic ovary syndrome(PCOS)with chronic stress state,to explore the impact of adverse psychological stress on PCOS,and provide experimental basis for further research.Methods Thirty-two 6-week-old SPF SD female rats were randomly divided into blank group,chronic stress group(CUMS),polycystic ovary syndrome group(PCOS),polycystic ovary syndrome with chronic stress group(PCOS+CUMS)by random number table method,with 8 rats in each group.The blank group received normal drinking water and food.The CUMS group simulated chronic psychological stress state with chronic unpredictable mild stress(CUMS)method.The PCOS rat model was established by using Letrozole.The rats in the PCOS+CUMS group were given Letrozole with CUMS method to establish a rat model which had both PCOS and chronic stress state.All models was continuously molded for 28 d.The changes of body mass in each group were observed.The behavior of rats was evaluated by open-field test(OFT)and sucrose preference test(SPT).The changes of ovarian histomorphology in rats were observed by hematoxylin-eosin staining.The levels of serum luteinzing hormone(LH),follicle stimulating(FSH)and free testosterone(FT)were determined by enzyme-linked immunosorbent assay(ELISA),and the ratio of LH/FSH was calculated.The secretion of 5-hydroxytrypamine(5-HT)and its metabolite 5-hydroxyindoleacetic acid(5-HIAA)in hippocampus was determined by high performance liquid chromatography-electrochemical detection(HPLC-ECD).Results After making model,the body weight,serum FT level and LH/FSH ratio of PCOS group and PCOS+CUMS group were higher than those of the blank group,the difference was statistically significant(P<0.05).Multiple cystic dilated follicles were seen in the ovary of rats in the PCOS group,while polycystic changes in the ovarian tissue of rats in the PCOS+CUMS group were more pronounced.The horizontal movement score,vertical movement score,sucrose preference and 5-HT content in rats’hippocampus of CUMS group and PCOS+CUMS group were lower than those of blank group(P<0.05),and 5-HIAA content was higher than blank group,these differences were statistically significant(P<0.05).Conclusion The interaction between PCOS and adverse psychological stress can make the disease progress.Letrozole combined with CUMS can induce the animal model of PCOS with chronic stress state,and its ovarian pathological changes,endocrine disorders and behavioral changes are closer to clinical features.It can be used as a reliable animal model for studying the pathological and pharmacodynamic mechanisms of PCOS combined with psychological stress.