Influence And Intervention Of Passive Smoking On Learning And Memory Ability Of Mouse And Its Offspring

Objective The influence of smoking to smokers has been known to all, however, hazard of cigaret smog to passive smokers isn't taken into account carefully by people. It has been reported that 51.9 percent of non-smokers are suffering from passive smoking and women are import component. In our country, the rate of passive smoking of pregnant women is higher than 70 percent. A staff from Prevent Medical Science Academy of China that shows: toxins such as nicotine are found in uterus of pregnant women who never smoke, which displays smog can pollute the environment of uterus, at the same time, these toxins certainly affect embryo cells reproduction, polarization, and finally lead to an abnormal growth, for instance, a slower growth of neural system. Vitamin E and quercetin are both effective anti-oxidant, but it is still unclear whether VE and quercetin can protect nerval system of mice through crossing placenta barrier and blood-brain barrier. This thesis studies passive smoking influences in learning and memory ability. I hope the thesis can supports some valuable experimental data for eugenics. Methods 1. Experimental animals and groups Healthy and clean KunMing mice, female 30, male 96 (6 of them are used to reproduce), 5-week old, 18±2g. Made the females into control group, quercetin group, smoking group, smoking and quercetin group, smoking and vitamin E group and smoking, quercetin and vitamin E group. Each group contains 5 mice. In different-time-smoking model, 90 male mice were used. These mice were made into control group and smoking group, and the latter could be classified into 1d, 1w, 2w, 4w, 8w group respectively, 15 mice each group. 2. Toxins infection ways and intervening measures Took female mice into dynamic passive smoking measure,exposured 6h/d, 5d/w for three months.After that, put one male mouse in every cage. After femal mice gave birth to offspring , selected the male offspring for poison, 15 mice each group.On the other hand take different exposure time as 1d, 1w, 2w, 4w and 8w for poison.Vitamin E: 100mg/kg/d, quercetin: 80mg/kg/d. 3 Figures and Methods 3.1 Water maze test of passive smoking mice and its offspring: special water maze. 3.2 long-term potentiation(LTP) in brains of passive smoking mice and its offspring. 3.3 Using the reverse transcription-polymerase chain reaction (RT-PCR) to test expression of nNOSmRNA . 3.4 Expression of AchE, NOS and NO in brains of mice 3.5 Test of neuron apoptosis: flow cytometer. 3.6 DNA damage in neuron of offspring mice :tested by comet assay. 3.7 Trough hippocampal neurons culture to test neuron livability,neuron apoptosis, and DNA damage in neuron. Results 1 The effect of passive smoking on the spacial learning ability and memory of mice and their offspring The swimming latency of every smoking groups were lower than control group at the same time, in which the groups of smoking for 1d, 1w, 4w, 8w, there had obvious difference compared with control group (P<0.05),the groups of smoking at different latency had no obvious difference(P>0.05). With the smoking time prolonging of smoking group,the swimming error numbers were increasing too ,and those for 4w and 8w group were higher than the groups of smoking for 1d, 1w and 2w. There had obvious difference (P<0.05). The water maze latency test of 1d, 4d, 8d and 12d in offspring mice , every groups had obvious difference (P<0.05). However there had no obvious difference in the swimming error numbers of offspring mice(P>0.05). 2 Influence on long-term potentiation(LTP)in brains of passive smoking mice and there offspring.The results in vivo showed that short-term smoking inhibited formation of long-term potentiation in the hippocampal dentate gyrus and CA1 areas. But with increasing of smoking peroid long-term potentiation increased, suggested that long-term passive smoking could lead to increasing of excitability of nerve cell and plasticity of nerve synapse. 3 Effect of CSE on nerve center neuron. Study in cell level showed that nicotine in high concentration (1:2, 1:5) influence nerve cells. Low concentration nicotine (1:20,1:175, 1:1750) had higher effect to control,there had obvious difference(P<0.05=. Apoptosis of neurons treated with CSE lower than control.Especially neurons had the lowest apoptosis when CSE concentration was1:1750 ,and had not find DNA damage in nerve cell. 4 Influence of NO, AchE, NOS and relative gene of passive smoking mice and offspring Using the reverse transcription-polymerase chain reaction (RT-PCR), as a hamiquantity assay, neuronal nitric oxide synthase (nNOS) mRNA levels in the mice hippocampus of smoking exposure in different period were investigated. Conclusion showed that nNOS mRNA expression of smoking mice and there offspring had no obvious difference. Expression of AchE and NOS of smoking mice decreased . Expression of NO and AchE of offspring mice were heighten ,and there had obvious difference(P<0.05). 5 Intervention effect of antioxidant Passive smoking influenced learning and memory ability of mice. Through antioxidant intervention could decreased restrain effect. LTP of intervention group with quercetin was higher than control group. Expression of NOS decreased in intervention group of VE and quercetin ,and which was prior to other groups. VE had the most striking effect on decreasing nerval transmitter. Conclusion 1 Influence on spacial learing and memory ability of passive smoking mice and offspring It could decreased spacial learing and memory ability of offspring by passive smoking in pregnant.On the other hand ,It could accelerated learing and memory ability of smoking mice. 2 Influence on long-term potentiation(LTP)of passive smoking mice and there...