夏天无总生物碱对痴呆大鼠学习记忆障碍及中枢胆碱能神经系统功能的影响

目的　观察夏天无总生物碱 (Xiatianwutotalalkaloids,XA)对喹啉酸损毁海马所致大鼠学习记忆障碍和中枢胆碱能神经系统功能的影响。方法　采用双侧海马CA1区微注射喹啉酸造成大鼠学习记忆障碍模型 ,在造模前 1wk至造模后 3wk内 ,大鼠每天igXA 0 2 5 ,0 5 ,1mg·kg-1。采用三等分Y迷宫测定大鼠学习记忆能力 ,并采用比色法检测海马乙酰胆碱酯酶 (acetylcholinesterase ,AChE)活性和大脑皮层乙酰胆碱 (acetylcholine ,ACh)含量的变化。结果　大鼠双侧海马内微注射喹啉酸可引起大鼠学习记忆功能障碍 ,海马中AChE活性下降 ,大脑皮层ACh含量减少 ;XA可显著改善喹啉酸诱导的痴呆大鼠学习记忆功能障碍 ,同时明显抑制模型大鼠海马的AChE活性 ,提高大脑皮层ACh含量。结论　XA可改善喹啉酸损毁海马造成的痴呆大鼠学习记忆功能障碍 ,而其机制可能与抑制脑AChE活性 ,从而提高ACh含量 ,增强中枢胆碱能系统的功能有关。

Effects of Xiatianwu total alkaloids on learning and memory impairment and the central cholinergic function in amnesic rats

Aim To observe the effects of Xiatianwu tota l alkaloids ( XA ) on learning and memory impairment and the central cholinergic f unction in rats with quinolinic acid microinjected into bilateral hippocampus. Methods Alzheimers disease (AD) rat models were made by damagin g bilateral hippocampus with quinolinic acid (150 nmol in 2 μl for each hippoca mpus). XA 0.25, 0.5, 1 mg·kg -1 was administrated ig from 1 week before model established to 3 weeks after model established. Y-maze was used to measur e the learning and memory ability. The activity of the acetylcholinesterase ( AC hE ) in hippocampus and the contents of acetylcholine ( ACh ) was determined by spectrophotometry. Results Microinjection of quinolinic acid in to the rats hippocampus induced learning and memory dysfunction (P<0.01), a nd decreased the activity of AChE in hippocampus and the contents of ACh in cere bral cortex (P<0.01). XA 0.5, 1 mg·kg -1 significantly improved lear ning and memory impairment in quinolinic acid treated rats (P<0.01), and ma rkedly reduced the activity of AChE in hippocampus and increased the contents of ACh in cerebral cortex(P< 0.01,P<0.05).Conclusion X A can ameliorate the learning and memory deficit of AD model rats and the mechan ism may be its involvement in inhibiting the AChE activity, and increasing the contents of ACh, enhancing the function of central cholinergic system.