维生素C、E对氢化可的松所致大鼠学习记忆功能损伤的保护作用

Protective Effect of Vitamin C and Vitamin E on Damage of Learning and Memory Functions in Rats Induced by Hydrocortisone

为探讨慢性应激对学习记忆功能过氧化损伤的可能机制以及维生素 C(VC)与维生素 E(VE)对慢性应激所致学习记忆功能损伤的抗过氧化保护作用 ,本实验在反复给予大鼠氢化可的松 (HC)建立慢性应激损伤学习记忆功能的动物模型基础上 ,同时给予 VC、 VE后观察大鼠学习记忆成绩、海马形态以及血、海马超氧化物歧化酶 (SOD)与丙二醛 (MDA)含量的变化。发现长期给予 HC的大鼠 :1在 Y-迷宫中的学习记忆成绩下降 ,15次正确数分别由对照组的 10 .38± 1.4 1、 11.5 0± 2 .0 7降为 7.88± 1.73(P<0 .0 1)、 10 .0 0± 2 .2 0 ;2海马 CA1 区发生大量神经细胞核固缩的形态学改变 ,核固缩细胞数由对照组的 (3.2 0± 2 .4 0 )个 / mm线长度增为 (98.4 0± 2 0 .70 )个 / mm线长度 (P<0 .0 1) ;3血、海马 SOD含量减少 ,由对照组的 (134.5 7± 1.2 6 ) U/ ml、 (71.2 3± 3.73) U/ m l降为 (74 .79± 5 .4 7) U/ ml(P<0 .0 1)、 (42 .87± 2 .76 ) U/ ml (P<0 .0 1) ;MDA含量增加 ,由对照组的 (4.76± 0 .73)μm ol/ L、 (130 .89± 30 .6 2 )μmol/L 增为 (9.4 8± 1.4 5 ) μmol/ L (P<0 .0 1)、 (2 15 .6 2± 6 0 .37) μm ol/ L (P<0 .0 5 )。同时给予 VC、VE可使上述指标明显改善 :学习记忆成绩提高为 11.2 5± 1.2 8(

In order to investigate the possible mechanism of peroxidative damage on learning and memory functions under chronic stress and the protective effects of antioxidation of vitamin C (VC) and vitamin E (VE) on the damage of learning and memory functions, a rat model of peroxidative damage of learning and memory functions under chronic stress induced by repetitive injection of hydrocortisone (HC) was established. Antioxidative effect of VC and VE on the damage was observed at the same time. The results were as follows: In the rats treated with long term HC, the accurate number of 15 times of learning and memory ability determined by Y maze was decreased from 10 38±1 41, 11 50±2 07 in the control group to 7 88±1 73( P <0 01), 10 00±2 20,respectively;pyknosis of the neuron nuclei in hippocampus CA 1 was widespread and the number of pyknosis per mm length was increased from 3 20±2 40 in the control group to 98 40±20 70( P <0 01); The contents of superoxide dismutase (SOD) were significantly decreased from 134 57±1 26 U/ml, 71 23±3 73 U/ml in the control group to 74 79±5 47 U/ml ( P <0 01), 42 87±2 76 U/ml ( P <0 01), but malondialdehyde (MDA) was markedly increased from 4 76±0 73 μmol/L, 130 89±30 62 μmol/L to 9 48±1 45 μmol/L ( P <0 01), 215 62±60 37 μmol/L( P <0 05)in blood and hippocampus, respectively. In the rats treated with VC and VE simultaneously, the above results were obviously improved as follows: the accurate number of the learning and memory ability was increased to 11 25±1 28 ( P <0 01), 11 75±2 43;the number of pyknosis was decreased to 8 30±4 60 ( P <0 01);the contents of SOD were increasd to 108 97±9 16 U/ml ( P <0 01), 66 48±3 37 U/ml ( P <0 01) and MDA decreased to 4 26±0 87 μmol/L ( P <0 01), 106 07±24 34 μmol/L ( P <0 01) in blood and hippocampus. These results suggest that peroxidative damage may be one of the causes for the injury of learning and memory under chronic stress, and VC and VE may have protective effect.