DHA和EPA对慢性应激诱导大鼠抑郁样行为和杏仁核相关基因表达影响比较

Comparison Between Effects of DHA and EPA on the Depression-like Behavior and the Expression of Amygdala-related Genes in Rats Induced by Chronic Stress

【目的】比较二十二碳六稀酸(DHA)和二十碳五稀酸(EPA)改善慢性不可预测温和应激(CUMS)诱导的大鼠抑郁样行为的作用机制。【方法】应用糖水偏好实验测定糖水偏好度,强迫游泳实验测定不动时间,荧光定量PCR检测杏仁核脑源性神经营养因子(BDNF)、其受体酪氨酸激酶受体(TrKB)和神经营养素(p75NTR)基因表达。【结果】与对照组相比,CUMS组大鼠糖水偏好度、BDNF和TrKB基因表达显著降低(P﹤0.05),而不动时间和p75NTR基因表达显著升高(P﹤0.05);给予DHA和EPA喂食治疗,可显著改善CUMS诱发的大鼠快感缺乏,绝望行为以及BDNF和TrKB的表达(P﹤0.05);DHA提高BDNF的表达作用显著优于EPA,而EPA对降低不动时间和p75NTR的表达作用显著优于DHA(P﹤0.05)。【结论】DHA和EPA通过调控不同基因表达改善CUMS诱导的抑郁样行为变化。

【Objective】This study aims to investigate and compare the effects of DHA and EPA on depressive-like behavior induced by the chronic unpredictable mild stress(CUMS),and explore their mechanisms in CUMS rat model of depression.【Methods】Sucrose preference test was performed to analyze sucrose preference,while forced-swimming test was performed to analyze immobility time.Quantitative Real-time PCR(qRT-PCR)was performed to detect the expression of brain derived neurotrophic factor(BDNF)and its two receptors,tyrosine kinase B(TrK B)and p75 neurotrophin receptor(p75NTR)genes in rat amygdala.【Results】Compared to control group,the sucrose preference,mRNA expression of BDNF and TrK B were significantly decreased(P<0.05),but immobility time and the expression of p75NTR were significantly increased in CUMS group(P<0.05).DHA and EPA improved the depression-like symptoms of anhedonia and despair,and attenuated BDNF and TrK B mRNA expression(P<0.05)in the CUMS group.Simultaneously,compared with EPA,DHA showed better effect on promoting the expression of BDNF(P<0.05).For the immobility time and 75NTR mRNA expression,EPA showed more pronounced decreasing effects than DHA(P<0.05).【Conclusion】These data suggest that DHA and EPA could improve CUMS-induced depression-like behavior via modulating different gene expressions.