神经源型一氧化氮合酶C276T基因多态性与抑郁症相关分析

目的测定抑郁症患者抗抑郁剂治疗前后血浆一氧化氮（NO）水平变化,旨在探讨神经源型一氧化氮合酶（nNOS）基因C276T多态性与血浆NO浓度及抑郁症发病相关性。方法采用硝酸盐还原酶法测定正常对照组及抑郁症患者治疗前后血浆NO水平;全部受试者取全血标本提取基因组DNA,并采用PCR-RFLP方法对nNOS基因C276T多态性进行基因分型。结果患者组疗前血浆NO水平为（76.8±31.6）μmol/L显著高于疗后[（66.9±25.7）μmol/L,P=0.044]及正常对照组[（64.2±33.3）μmol/L,P=0.02],两组疗后血浆NO水平相比差异无显著性（P=0.588）;根据PCR-RFLP结果,nNOS基因可见两种等位基因条带C、T,组成三种基因型CC、CT、TT,两组等位基因及基因型分布频率差异无显著性（均P〉0.05）,且携带不同基因型者之间血浆NO水平差异亦无显著性（均P〉0.05）。结论血浆NO浓度增高可能是抑郁症发病的影响因素;nNOS基因C276T多态性可能不直接影响血浆NO浓度,也不是抑郁症发病的主要基因因素。

Study of neuronal nitric oxide synthase gene polymorphism in depressed patients

Objective To analyze the alterlation of plasma nitric oxide（NO） concentrations in depressed patients,and also to investigate whether neuronal nitric oxide synthase（nNOS） gene C276T polymorphism was associated with plasma NO concentrations and depression.Methods Plasma NO concentrations were measured in depressed patients before and after antidepressant treatment and normal controls by spectrophotometer.Genotyping was performed using PCR-RFLP techniques both in patients and normal controls.Results The plasma NO concentrations in acute episode untreated depressed patients（76.8±31.6）μmol/L were significantly higher than that in the patients after 8-weeks antidepressant treatment[（66.9±25.7）μmol/L,P=0.044]and normal controls [（64.2±33.3）μmol/L,P=0.02].There was no significant difference between the plasma NO concentrations in treated patients and nomal controls（P=0.588）.Neither genotype（P0.05） nor allelic frequencies（P0.05） showed significant difference between patients and normal contrals for nNOS gene C276T polymorphism.Furthermore,genotypes of eNOS were not associated with plasma NO concentrations（P0.05）.Conclusion These data provide a possibility that increased level of plasma NO may play a role in the pathogenesis of depression.The nNOS gene C276T polymorphism may not be important in plasma NO concentrations and the susceptibility to depression.