Effects Of Cigarette Smoke And Chronic Stress On Learning,Memory And Reproductive Function In Rats

Objective: To study the effects of cigarette smoke and chronic stress on learning,memory and reproductive function in rats.Methods: 40 healthy SD rats,10 in each group,50% males,were randomly divided into control group,cigarette smoke group,chronic stress group and joint exposure group.The control group received no treatment;The rats in the cigarette smoke group were exposed to the respiratory tract statically,10 cigarettes each time,once a day for 30 minutes;the chronic stress group was randomly given one chronic stress daily from 5 chronic stress regimens,each chronic stress mode was not applied continuously;the joint exposure group chronic stress treatment(treatment same as chronic stress group)was performed daily on the basis of cigarette smoke exposure(treatment same as cigarette smoke group);the experiment lasted 12 weeks.Rats were tested for Morris water maze at 2,4,8,10,and 12 weeks of exposure to assess their learning and memory abilities;after 12 weeks,rats were sacrificed to calculate brain,ovary,and testicular organ coefficients;serum Cort was determined Concentration,Ach,ChAT,FSH,GnRH,IGF-1,LH,E2 content and AchE activity.Observe the histopathological changes of rat brain,ovary and testis;detect the expression of key mRNA and protein on PI3 K / AKT signaling pathway in brain,ovary and testis by immunohistochemical staining,RT-PCR and Western blot.Results: 1.Compared with the control group,the serum Cort content in the chronic stress group increased(P<0.05);2.At the second week of the experiment,the escape latency of the joint exposure group was shortened compared with the chronic stress group(P<0.05);At week 10 of the experiment,compared with the control group,the escape latency of rats in each exposure groupincreased(P<0.05);compared with the control group,the serum Ach content of rats in each exposure group decreased(P<0.05),chronic stress group Serum ChAT content decreased and AchE activity increased(P<0.05);HE staining showed that the brain tissue of rats in each exposure group showed neuronal nucleus contraction,meningeal vascular congestion and congestion;compared with the control group,cigarettes Smoke,chronic stress and joint exposure all cause up-regulation of PTEN gene mRNA expression in brain tissue,PI3 K,AKT,mTOR positive area ratio,mRNA expression and protein content decreased(P<0.05);3.Compared with control group,chronic stress And the joint exposure group decreased the ovarian organ coefficient(P<0.05);compared with the control group,the levels of serum GnRH,IGF-1,LH,and E2 in the cigarette smoke group decreased(P<0.05),and the serum FSH,IGF-1,LH,E2 content decreased(P<0.05),joint exposure The serum FSH,IGF-1 and LH levels in rats decreased(P<0.05);compared with the control group,cigarette smoke,chronic stress and joint exposure will cause different degrees of congestion and compensatory hyperplasia of ovarian and testicular tissues in rats.Causes atrophy of the oocyte nucleus,and shrinkage of the germ cell nucleus in the testis tissue;compared with the control group,cigarette smoke,chronic stress,and joint exposure can lead to PI3 K,AKT,mTOR positive area ratio,mRNA expression The protein content decreased(P<0.05).Conclusion: 1.Cigarette smoke,chronic stress alone and combined exposure can reduce the learning and memory ability of rats.2.Cigarette smoke,chronic stress alone and combined exposure can cause reproductive damage in rats.