Study On The Effect Of Letrozole In Guizhou Xiang Pig Testis Cells

Endogenous estrogen is a kind of steroid compounds which have a wide range of biological activities.It plays an important role in the development of reproductive system and reproductive activity of female and male animals.Studies have shown that endogenous estrogen play a biological role in addition to estrogen dependent in vitro,but also through the regulation of sex hormones,gonadotropin and NO expression and thus affect the reproductive function of male.In male animals,estrogen is mainly derived from the E2 catalyzed by aromatase catalyzed by T,so the inhibition of aromatase activity can effectively reduce the level of E2 in male animals.Letrozole（Letrozole）is the third generation of non steroidal aromatase inhibitors,it does not change the animal body secretion of gonadotropin and androgen,but can effectively reduce the level of estrogen and the male animal does not affect the synthesis of other steroid hormones,is a good reagent of endogenous estrogen.So in this experiment we based on Guizhou Xiang Pig by using letrozole as research reagents.With in vivo and in vitro methods,by immunohistochemistry,ELISA and cell culture technology to analysis of Guizhou Xiang Pig endogenous estrogen on spermatogenesis in estrogen receptor,sex hormone,gonadotropin,nitric oxide synthase expression and other factors spermatogenesis.Through this experiment,to provide a comprehensive understanding of the pig testis development and the basic information of how endogenous estrogen influences the development of male mammal testis.The results of in vivo and in vitro studies were obtained:1、Xiang Pigs were found to reduce endogenous estrogen can make the number of testicular germ cel s was significantly reduced（P <0.05）,and to promote the young pig sertoli cell number was significantly increased（P<0.05）;And in vitro,reduction of the endogenous estrogen can make cultured testis cel s and sertoli cell activity were significantly reduced（P<0.05）.The results showed that effects of juvenile testis of Xiang pig cell proliferation by estrogen,and in vivo test found that the number of sertoli cel s varies,indicating the proliferation of Sertoli cel s not only by the effects of estrogen,was also affected by other factors.2、Xiang Pigs were found to reduce endogenous estrogen can significantly reduced E₂ and luteinizing hormone content（P<0.05）,T and FSH content increased significantly（P<0.05）;And the cultured testicular cel s of experimental group E₂ content of culture medium was significantly reduced（P<0.05）,T increased significantly（P<0.05）.The results of in vitro and in vivo studies showed that the changes of endogenous estrogen levels could affect the synthesis and secretion of reproductive hormones.3、Xiang Pigs were found to reduce endogenous estrogen can make the pig body of eNOS,iNOS,nNOS,NOS content and eNOS expression were significantly increased（P<0.05）,and the expression of estrogen receptor（P <0.05）was significantly reduced.At the same time,it was found that eNOS was expressed only in the cytoplasm of testicular germ cel s,but the expression of ER receptor in the testis germ cel s and Sertoli cel s,but ER was only expressed in the nucleus of testicular germ cel s.From all these things,we come to the conclusion that once decrease the content of endogenous estrogen can make seminiferous tubules diameter and area,the number of germ cel s increased,but the number of Sertoli cel s increased;ERs,eNOS,iNOS,nNOS,and NOS,sex hormone and gonadotropin expression showed a degree of regularity,may play an important role in modulate the growth,development and maturation of the testicles.While estrogen may be through affecting the expression of ERs and NOS to play an equality role,resulting in juvenile pig reproductive system abnormalities.