摘要
目的探讨邻苯二甲酸二丁酯(DBP)对大鼠睾丸的损害作用及与细胞外调节蛋白激酶(ERK)信号通路激活、缝隙连接损伤关联性。方法 SD大鼠随机分为3个DBP剂量组(50、500、1 000 mg/kg)和溶剂对照组,经口灌胃染毒,每日1次,持续5周。酶联免疫吸附试验检测大鼠血清卵泡刺激素(FSH)、黄体生成素(LH)、睾酮等生殖激素水平;精子分析仪分析精子密度、活率和总畸形率;苏木素-伊红染色法观察睾丸组织结构变化;Western blot法检测ERK1/2和p-ERK蛋白表达;RT-PCR法检测缝隙连接蛋白43(Cx43)mRNA表达。结果与对照组比较,中、高剂量DBP组大鼠血清睾酮水平[(6.65±0.97)、(3.57±0.54)nmol/L]明显降低(P<0.05),高剂量DBP组大鼠精子密度(64.71±11.36)10~5个/mL显著降低(P<0.05),中、高剂量DBP组大鼠精子总畸形率[(13.64±1.68)%、(19.54±2.86)%]明显升高(P<0.05);随DBP剂量升高大鼠睾丸组织结构损伤程度增加;与对照组比较,中、高剂量DBP组大鼠睾丸组织中p-ERK表达明显升高,各剂量DBP组大鼠睾丸组织中Cx43 mRNA表达均明显下降,差异具有统计学意义(P<0.05)。结论 DBP可激活ERK通路、下调Cx43表达,引起大鼠睾丸组织结构和功能损伤。
Objective To investigate the adverse effect of dibutyl phthalate （DBP） on testis of rat and to explore the relationship between extracellular regulated protein kinase （ERK） signaling pathway and gap junction injury. Methods Four groups of Sprague-Dawley （SD） rats were administered with 50,500 or 1000 mg/kg DBP or corn oil （control group） by gavage once a day continuously for 5 weeks. Follicle-stimulating hormone （FSH）, luteinizing hormone （LH） and testosterone （T） in serum were detected with enzyme-linked immunosorbent assay （ELISA）. The density, mobility and overall malformation rate of sperm in epididymis were evaluated with sperm morphology analyzer. The histopathological changes in testes of the rats of each group were observed with haematoxylin and eosin （HE） staining. Western blot was applied to quantify the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/2） and phosphorylated extracellular signal-regulated kinase 1 and 2 （p-ERK1/2） protein which are responsible for ERK signaling pathway. The mRNA expression of connexin 43 （ Cx43 ）, the predominant protein of gap junction, was estimated by reverse transcriptase PCR （RT-PCR）. Results The serum testosterone level （ 6. 65 ±0. 97 and 3.57 ±0. 54 nmol/L） of the rats exposed to moderate and high dosage DBP decreased significantly compared to that of the control （ both P 〈 0. 05 ） ; the sperm density （ 64. 71 ± 11.36 × 10 000/mL） of the rats of high dose DBP exposure group decreased significantly （P 〈0. 05） ,while the overall malformation rate of sperm （ 13.64 ± 1.68% and 19.54 ±2.86% ） for the rats exposed to moderate and high dosage DBP increased significantly （ both P 〈 0.05 ）. The damage severity of testis tissues of the rats was positively related to DBP exposure dose. The expression of p-ERK1/2 protein in testis tissues for the rats with moderate and high dose DBP exposure increased significantly （ both P 〈 0.05 ） but the expression of Cx43 mRNA decreased for the rats exposed to various doses of DBP significantly compared to those of the control rats （ P 〈 0. 05 ）. Conclusion DBP could activate ERK signaling pathway and down-regulate Cx43 expression, resulting in structure and function damage in testis tissue in rats.
出处
《中国公共卫生》
CAS
CSCD
北大核心
2017年第2期206-210,共5页
Chinese Journal of Public Health
基金
吉林省科技发展计划项目(201205038
20130101141JC)
吉林省教育厅计划项目(2014211)
