轻度认知障碍和阿尔茨海默病患者血清中兴奋性氨基酸的含量

Serum excitatory amino acids concentrations in patients with amnestic mild cognitive impairment or Alzheimer's disease

目的研究遗忘型轻度认知障碍(amnestic mild cognitive impairment,aMCI)及阿尔茨海默病(Alzheimer’s disease,AD)患者血清中兴奋性氨基酸(EAAs)含量的变化,探讨 EAAs 在二者发病中的作用。方法使用高效液相法对30例 aMCI、32例 AD 患者以及34名健康对照者血清中EAAs[谷氨酸、天门冬氨酸(Asp)]及 EAAs N-甲基-D-Asp(N-methyl-D-aspartate,NMDA)受体的协同激动剂甘氨酸、丝氨酸、丙氨酸含量进行测定和比较。结果 aMCI 组血清中的谷氨酸[(39.6±22.1)μmol/L]和丙氨酸[(282.5±71.3)μmol/L]含量高于健康对照组[(30.0±11.6)μmol/L,P=0.044;(240.7±46.3)μmol/L,P=0.007]。而 AD 组血清中谷氨酸[(42.2±21.8)μmol/L]、甘氨酸[(464.2±142.6)μmol/L]明显高于健康对照组[P=0.010;(395.6±88.8)μmol/L,P=0.010];但aMCI 组和 AD 组之间差异无统计学意义。AD 组血清中 Asp(P=0.011)和谷氨酸(P=0.017)的含量与 MMSE 得分呈正相关,轻度 AD 患者血清中这两种氨基酸含量[(42.1±21.3)、(55.0±29.0)μmol/L]要高于中重度 AD 患者[(25.4±9.2)μmol/L,P=0.023;(34.6±11.1)μmol/L,P=0.036]。结论 EAAs 可能参与 AD 的发病,并且与 AD 的严重程度存在一定的相关性;aMCI 患者也存在着 EAAs 代谢的紊乱,提示其可能和 AD 有着类似的发病机制。

Objective To figure out changes of serum excitatory amino acids （EAAs） levels in patients with amnestic mild cognitive impairment （aMCI） and Alzheimer＇ s disease （AD）. Methods The levels of serum EAAs was assessed in 34 cognitively normal control subjects, 30 patients with aMCI, and 32 patients with AD using high performance liquid chromatography （HPLC）. Results ① Higher serum concentrations of glutamate（ （39. 6±22. 1 ） μmol/L） , Marline（ （282. 5 ±71.3） μmol/L） were found in the aMCI patients （ P = 0. 044, P = 0. 007 ）, and higher serum concentrations of glutamate （ （42. 2 ± 21.8 ） μmol/L）, glycine （ （464. 2 ± 142. 6） μmol/L） were found in the AD patients than in the control subjects （P =0. 010,P =0. 010）. ②No statistically significant difference of EAAs level between the aMCI and AD groups was found. ③ A close and positive correlation between the serum concentrations of glutamate, aspartate and the mini-mental status examination scores were found in AD patients： the 2 amino acid levels were higher in patients with mild dementia （ （42. 1 ± 21.3 ）, （ 55.0 ± 29. 0） μmol/L） than those with moderate or severe dementia （ （25.4 ± 9. 2 ） μmol/L, P = 0. 023 ; （ 34. 6 ± 11. 1 ） μmol/L, P = 0. 036 ）. Conclusion EAAs, correlating with the severity of the condition, play a significant role in AD, while aMCI patients also have disturbance of metabolism of EAAs, indicating that it has similar pathogenesis to AD.