短期暴露邻苯二甲酸酯对雄性生殖系统发育和功能影响的实验研究

发布时间：2018-03-16 04:27

本文选题：DEHP　切入点：未成熟睾丸　出处：《重庆医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的:探讨新生雄性大鼠短期暴露环境内分泌干扰物邻苯二甲酸二(2-乙己基)酯DEHP对其雄性生殖系统发育和功能的影响。通过分析Nrf2和notch信号通路中关键信号分子Nrf2和notch1蛋白表达情况,以及相关氧化应激损伤指标检测,初步探讨Nrf2以及notch信号通路在DEHP致未成熟睾丸发育损伤的作用。方法:新生雄性大鼠42只分为:对照组(玉米油)、DEHP 250mg/kg暴露组、DEHP 500mg/kg暴露组。在生后第1到第15天,分别每日经口灌胃玉米油和DEHP。PND36时,每组随机取6只,经10%水合氯醛麻醉下取材。PND90时,行交配实验后,全部麻醉下取材,附睾组织做精子计数和精子畸形率的检测。在PND1,PND10,PND20,PND36以及PND90时,测量各组雄鼠的AGD。PND36取得的睾丸组织行HE染色、氧化应激相关指标检测以及关键蛋白notch1、Nrf2的表达。结果:与对照组相比,DEHP 250mg/kg暴露组的AGD长度偏低,而睾丸、附睾脏器系数、精子计数、精子畸形率以及以及交配实验结果无明显差异,睾丸组织可见生精上皮排列稍紊乱。DEHP 500mg/kg组的AGD长度、睾丸脏器系数较正常对照组偏低;附睾脏器系数、合笼实验结果与正常对照组比无显著性差异,但精子畸形率较正常组显著性增高,并且组织学上可见睾丸组织形态有所改变。DEHP 500mg/kg组,睾丸组织内ROS水平、SOD酶活性以及MDA较对照组明显增多,差异具有统计学意义,Nrf2蛋白以及notch1蛋白表达量降低;DEHP250mg/kg暴露组,其睾丸组织内ROS水平、SOD酶活性及MDA较对照组升高,但无统计学意义,Nrf2以及notch1蛋白的表达较对照组降低,差异有统计学意义。结论:新生雄性大鼠短期DEHP 500mg/kg暴露可导致其成年后精子质量的下降,突出表现在精子畸形率上;而DEHP 250mg/kg短期暴露对其成年后生殖功能影响不明显,但组织学上仍有轻微改变。DEHP的暴露可以引起睾丸组织氧化压力的增加,MDA水平升高,使Nrf2表达降低,可能间接影响notch信号通路,使notch1蛋白表达降低。
[Abstract]:Objective: to investigate the effects of environmental endocrine disruptor di-2-ethylhexyl phthalate (DEHP) on the development and function of male reproductive system in neonatal male rats. The key signal components in Nrf2 and notch signaling pathway were analyzed. The expression of Nrf2 and notch1 proteins, And the related indexes of oxidative stress injury, To investigate the effects of Nrf2 and notch signaling pathway on immature testicular development injury induced by DEHP. Methods: Forty-two newborn male rats were divided into two groups: control group (exposed to 250 mg / kg DEHP) and DEHP 500 mg / kg exposure group on the 1st to 15th day after birth. When corn oil and DEHP.PND36 were given orally daily, 6 rats in each group were randomly selected. After mating experiment, the samples were obtained under 10% chloral hydrate anaesthesia. Spermatozoa count and sperm abnormality rate were measured in epididymal tissues. During PND1, PND10, PND20, PND36 and PND90, the testicular tissues obtained from AGD.PND36 of each group were stained with HE. Results: compared with the control group, the AGD length of DEHP 250 mg / kg exposure group was lower, while testicular, epididymal organ coefficient, sperm count, testicular, epididymal organ coefficient, spermatozoa count. There was no significant difference in the rate of sperm abnormality and the results of mating test. The testicular tissue showed that the AGD length, testis organ coefficient and epididymal organ coefficient of the spermatogenic epithelium were slightly disordered, and the testicular organ coefficient was lower than that of the normal control group. There was no significant difference between the cage test and the normal control group, but the rate of sperm malformation was significantly higher than that of the normal group, and histologically, the testicular tissue morphology was changed in the group of 500 mg / kg DEHP. The activity of ROS and MDA in testicular tissue were significantly higher than those in the control group. The expression of Nrf2 protein and notch1 protein were significantly decreased in the testis exposed to 250 mg / kg DEHP, and the activity of ROS and MDA in the testis were higher than those in the control group, and the expression of Nrf2 protein and notch1 protein in the testicular tissue was significantly higher than that in the control group. However, the expression of Nrf2 and notch1 protein in neonatal male rats was significantly lower than that in control group. Conclusion: the short-term exposure of DEHP 500mg / kg in neonatal male rats can lead to the decrease of sperm quality in adulthood, especially in the rate of sperm abnormality. However, the short-term exposure of DEHP 250 mg / kg had no obvious effect on the reproductive function after adulthood, but there was still a slight histological change. DEHP could increase the oxidative pressure of testis and increase the level of Nrf2, which may indirectly affect the notch signaling pathway. The expression of notch1 protein was decreased.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R114

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