Effect Of Ethephon On Apoptosis Of Spermatogenic Cells And Sex Hormone Levels In Adolescent SD Rats

BackgroundOver the past half-century,Infertility has become a very serious social problem.male infertility is up to 50% in all infertile patients,But the reasons of most infertile patients are unknown.Environmental factors are considered to be the main cause of male infertility,Which has been caused great concern to the scholars.Ethephon is used one of the plant growth regulator and has been used the most widely.It can promote plant flowering and fruit ripening earlier,which was mainly used to improve plant production and mature Fruit ripening.In the production process,the farmers purpuse to pursuit the maximum benefit,they ues the ethephon in an illegal way.Renently an investigation found that there are much pesticide residue in food.Foreign scholars found that ethylene can make the protein phosphorylation,which can change biological activity in cells.Domestic scholars found that the ethephon can affect the reproductive system,the neuroendocrine system,the immune system and the nervous system in rats.There are no reports about the effect on adolescent male reproductive system in the living organisms,Therefore we use different doses of Ethephon on the ad-olescent male SD rats,at different times to observe the weight,the apoptosis of testicular cells,sex hormones,to investigate the effects of Ethephon on the reproductive toxicity and sex hormone levels or in a time-and dose-dependent manner?ObjectivesTo observe the common living status was detected including daily diet,activity,urine and stool,body mass and fur,weight change,Changes in Serum Sexual Hormone Levels,the apoptosis of testicular cells,we establish the model of SD rats,who have been exposed to different doses of Ethephon.Then we investigate the effects of Ethephon onthe reproductive toxicity and sex hormone levels.It can provide the safety of Ethephon on human and theory support for young and middle-aged male sterile provide theoretical support.MethodsThe male SD rats were randomly（from the random numner table）divided into groups: high dose（2000 mg/kg）,middle dose（1000 mg/kg）,low dose groups（500 mg/kg）and control group（the same amount of physiological saline）.they were given ethephon through stomach for 7d,14 d,21d,then stop using for one month.After those days,those mice were killed to detected toxicity of ethephon to testicle and T and E₂ content and biochemical indicator change,apoptosis.we observe the pathological changes of testis tissue by HE staining to,the apoptosis of germ cells were detected by terminal transferase labeling（TUNEL）;Blood sampling from the heart,Preservation after centrifugation,batch operation,the automatic chemical luminescence immunoassay analyzer for the determination of serum sex hormone levels.SPSS 20.0 statistical software was used for statistical analysis.Comparisons between groups were tested by One-Way ANOVA analysis and LSD test.P < 0.05 as a significant test standard.Results（at the same time-points.）1.Compared with the control groups,the body weights,testicular weights,MTD and the apoptosis index of the experimental groups were lower than the control group（P<0.05）;Compared with the control dose groups,all of them in the high and middle dose groups decreased significantly（P<0.01）;Compared with the middle high dose groups,all of them in the hight dose group had no significant difference（P> 0.05）;all of them in the low dose groups were not statistically significant than the control groups（P >0.05）.2.In 7 days and 14 days,the serum E2 level in high dose group compared with the middle dose group,the low dose group and the control group have statistical meaning（P< 0.05）;In 21 days,the serum E2 level in high dose group and he middle dose group compared with the low dose group and the control group have statistical meaning（P <0.05）;the serum E2 level in low dose group compared with the control group have no statistical meaning（P>0.05）。3.The level of T in High dose groups and middle dose groups are lower than which in the low dose groups and the control groups（P < 0.05）;Compared with the low and control groups,the level of T in the high dose groups decreased significantly（P < 0.01）;The level of T in the low dose groups were not statistically significant than the control groups（P > 0.05）.（the same dose group）1.Compared with the control groups,the body weight,the testis weight and MTD decreased with the extension of contacting time of ethephon,germ cell apoptosis index increased with the extension of contacting time of ethephon;The ethephon can affect the growth of body weight,testis weight,MTD,the cells apoptosis rate by One-Way ANOVA analysis and LSD test（P < 0.05）;2.The serum E2 level and T level in high dose group and middle dose group were gradually increased with the extension of time,but the trend is stable,one-way analysis of variance showed,a adose of ethylene had certain influence on serum E2 and T levels（P<0.05）.（30d later）Compared with the control groups,the body weights,testicular weights,MTD and the apoptosis index and the E2、T levels of the experimental groups have recovered close to the normal levels gradually（P>0.05）.Conclusions Ethephon on rats with certain reproductive toxicity induced testicular tissue structure change,sex hormone levels decrease and increase the apoptosis of spermatogenic cells,result in spermatogenic capacity is reduced,which may lead to male infertility is one of the main reasons.