胶质细胞源性神经营养因子对大鼠单侧隐睾组织中干细胞因子及抗氧化酶活性的影响

Effects of glial cell-derived neurotrophic factor on SCF protein and antioxidant enzyme activity in the testis of unilateral cryptorchidism rats

目的:探讨胶质细胞源性神经营养因子(GDNF)对大鼠隐睾睾丸组织中干细胞因子(SCF)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量的影响。方法:选取雄性SD大鼠左侧隐睾成功模型48只,体重(200±20)g,完全随机法分为4组,每组12只。A组为对照组,B组为GDNF 7 d组,C组为GDNF14 d组,D组为GDNF 21 d组。每组根据设定处理方式的不同分别进行处理,采集左侧睾丸并行生化指标(SOD、CAT活性及MDA含量)检测;TUNEL检测隐睾组织细胞调亡指数(AI);HE染色观察睾丸组织学形态;实时定量PCR法检测隐睾组织中SCF基因的表达情况,Western印迹检测各组隐睾组织中SCF蛋白表达情况。结果:与GDNF组相比,其中GDNF 14 d组中各项指标有明显变化;生精细胞凋亡明显减少,其中对照组、GDNF 7 d组、GDNF 14 d组、GDNF 21 d组AI分别为13.5±0.64、8.42±0.16、4.45±0.34、7.32±0.09。对照组与GDNF 14 d组相比差异有明显统计学意义(P<0.01),与对照组相比,各GDNF组生精细胞凋亡减少,SOD活性明显上升,MDA含量下降明显,SCF表达较对照组有明显增高,差异有明显统计学意义(P<0.01)。结论:GDNF对大鼠单侧隐睾组织生精功能具有保护作用,增强抗氧化酶系统的抗氧化能力,提高SCF表达含量,从而改善睾丸生育能力,其以GDNF 14 d时作用最明显。

Objective： To explore the effects of glial cell-derived neurotrophic factor （GDNF） on the stem cell factor （SCF）, superoxide dismutase （ SOD）, catalase （CAT） and malondialdehyde （MDA） in the undescended testis tissue of rats. Methods： Models of left cryptorchidism were made in 48 healthy male rats weighing （200±20） g and randomly divided into four groups： model control, GDNF 7 d, GDNF 14 d and GDNF 21 d. The rats in the latter three groups were killed at 7, 14 and 21 days after intravenous injection of GDNF, their left testes harvested for measurement of the activities of SOD and CAT and the content of MDA. The apoptosis index of spermatogenic cells was detected by TUNEL, the histological changes of the testis tissue observed under the light microscope,and the gene and protein expressions of SCF determined by real-time quantitative PCR and Western blotting, respectively. Results： The apoptosis indexes of spermatogenic cells were obviously decreased in the GDNF 7 d, GDNF 14 d and GDNF 21 d groups （8.42 ± 0.16, 4.45 ± 0.34 and 7.32 ± 0.09） as compared with that of the model control （13.5 ± 0.64）, with statistically significant difference between the GDNF 14 d and control groups （P 〈 0.01 ）. The SCF expression and SOD activity were remarkably increased while the MDA content markedly reduced in the GDNF groups in comparison with those in the model control （P 〈 0.01）. Conclu- sion ： GDNF had a protective effect on the spermatogenic function of rat testes with unilateral cryptorchidism. It could enhance the an- tioxidant enzyme activity of the antioxidant enzyme system, elevate the expression of SCF and thus improve the testicular reproductivity, which were best indicated in the GDNF 14 d group.