应激猪睾丸葡萄糖转运蛋白1和葡萄糖转运蛋白2的表达与定位

目的 探讨正常和热应激条件下，葡萄糖转运蛋白1（GLUT1）和葡萄糖转运蛋白2（GLUT2）在成年猪睾丸的表达和定位。 方法 性成熟长白公猪9头，随机分为3组。局部阴囊热刺激组（n=3），用自制电热毯置阴囊42 ℃加热1 h；环境热应激组（n=3），每天置于37～40 ℃猪舍环境3 h，连续7 d，每天于热处理结束后，将实验猪驱赶回21～25 ℃猪舍环境；对照组（n=3），饲养在21～25 ℃猪舍环境。局部热刺激6 h后和环境热应激处理结束24 h后，手术摘除双侧睾丸。用Real-time PCR、Western blotting和免疫组织化学技术检测猪睾丸组织内GLUT1和GLUT2的表达。 结果 Real-time PCR和Western blotting结果显示，与对照组相比，环境热应激组GLUT1蛋白和mRNA的表达差异不显著，局部阴囊热刺激组GLUT1蛋白和mRNA表达显著升高；环境热应激组和局部阴囊热刺激组，GLUT2蛋白和mRNA表达均显著升高。免疫组织化学结果发现，热处理前后，GLUT1蛋白在曲精小管内定位于精母细胞和圆形精子细胞；环境热应激组GLUT1蛋白染色与对照组相比，无明显差异，局部阴囊热刺激后，GLUT1染色变深，表达升高。热处理前后，GLUT2蛋白在曲精小管定位于生精细胞和支持细胞，环境热应激和局部阴囊热刺激导致GLUT2染色变深，表达升高。 结论 葡萄糖转运蛋白GLUT1和GLUT2表达于猪睾丸曲精小管，环境高温和阴囊局部热刺激导致GLUT1和GLUT2在猪睾丸的表达水平改变，提示这两种葡萄糖转运蛋白在猪精子发生过程中发挥重要作用。

Expression and localization of glucose transporter 1 and glucose transporter 2 under heat stress conditions

Objective To investigate the expression and localization of glucose transporter 1 (GLUT1) and glucose transporter 2 (GLUT2) in adult boar testis under normal temperature and heat stress conditions.Methods Nine adult boars (Landrace) were randomly divided into three groups.The self-made thermo-controlled 42 ℃ blanket was used in local scrotal heating group (42 ℃ for 1 hour) (n =3).The boars of environmental heat stress group (n =3) were kept in a thermally-controlled hot house (37-40 ℃,7 days,3 hours per day).After the daily heat treatment,the boars were back to the normal temperature.Three boars were assigned as control (n =3) and kept in normal temperature house (21-25 ℃).After 6 hours (local scrotal heating group) and 24 hours (environmental heat stress group) of heat treatment,the boar testes were surgically harvested.The expression of GLUT1 and GLUT2 were detected in boar testes by using Real-time PCR,Western blotting and immunohistochemistry.Results The results of Real-time PCR and Western blotting showed that the GLUT1 protein and mRNA expression levels in the environmental heat stress group did not have significantly differences compared with control group.The GLUT1 protein and mRNA expression levels in the local scrotal heating group significantly increased compared with control group.In environmental heat stress group and local scrotal heating group,the expression levels of GLUT2 protein and mRNA significantly increased compared with control group.Immunohistochemical results showed that GLUT1 protein in seminiferous tubules was expressed in spermatocyte and round spermatid before and after heat treatment.In environmental heat stress group,the immunostaining of GLUT1 protein did not have significantly differences compared with control group.After local scrotal heating,the immunostaining of GLUT1 protein was deeper than control group,and the expression level of GLUT1 protein was increased.Before and after heat treatment,the GLUT2 protein in seminiferous tubules was expressed in germ cells and sertoli cells.The environmental heat stress and the local scrotal heating resulted in increase of GLUT2 expression and deeper immunostaining.Conclusion Glucose transporter GLUT1 and GLUT2 are expressed in the seminiferous tubules of boar testes.Environmental heat stress and local scrotal heating result in changes of GLUT1 and GLUT2 expression levels in the boar testis.The result suggests that GLUT1 and GLUT2 play important roles in boar spermatogenesis.