血管内皮细胞生长因子及其受体2在慢性砷染毒大鼠睾丸中的表达及其意义

Expression and significance of VEGF and VEGFR2 in the testis of rats with chronic arsenic poisoning

目的:研究血管内皮细胞生长因子(VEGF)及其受体2(VEGFR2)在慢性砷中毒大鼠睾丸中的表达及意义。方法:健康清洁级雄性SD大鼠随机分为高、中、低剂量砷染毒组和对照(蒸馏水)组,采用经口自由饮用方式进行染毒,连续染毒6个月。H-E染色观察睾丸一般形态学变化,免疫荧光化学法对睾丸组织VEGF和VEGFR2的表达进行定位,采用实时荧光定量PCR法检测睾丸组织VEGF和VEGFR2的mRNA表达变化,流式细胞术观察精子的凋亡率。结果:与对照组比较,中、高剂量砷组大鼠体质量明显降低,睾丸组织质量也明显降低,而低剂量砷组大鼠体质量、睾丸质量、睾丸脏器系数差异无统计学意义。对照组睾丸结构正常,染砷组大鼠睾丸组织上皮结构疏松,层次排列紊乱,层次逐渐减少,精原细胞出现空泡样改变,睾丸间质充血、渗出等,尤其中、高剂量砷组有较明显的变化。与对照组比较,各染毒组VEGF和VEGFR2的mRNA表达水平均较低,砷染毒组大鼠精子凋亡率较高,差异均有统计学意义。结论:慢性砷中毒时,VEGF可能通过旁分泌-自分泌的方式参与调控大鼠睾丸的功能,VEGF及其受体2在砷中毒大鼠精子发生和发育过程中起重要作用。

Objective:To study the effect of chronic arsenic poisoning on expression of VEGF and VEGFR2 in the testis of rats and its effect on the apoptosis of sperms,and to provide theoretical basis for male infertility caused by arsenic poisoning.Methods:Forty male Sprague-Dawley rats were randomly divided into four groups:high dose arsenic infected group,middle dose arsenic infected group,low dose arsenic infected group and control group(distilled water group).Rats were treated with arsenism through drinking water for 6 consecutive months.At the end of the experiment,the general morphological changes of testis were observed by H-E staining,and the expression of VEGF and VEGFR2 was localized by immunofluorescence,the mRNA expression levels of VEGF and VEGFR2 were observed by Real-time PCR,the apoptosis rate of sperms was observed by flow cytometry.Results:The body weight of rats in the middle,high dose arsenic infected group was significantly lower than that in the control group and the testis weight was significantly lower than that in the control group.There was no statistically significant difference in the body weight,testis mass and testicular viscera coefficient of rats in the low dose group.Compared with control group,the mRNA expression levels of VEGF and VEGFR2 in each infected group were lower,and the differences were statistically significant.Compared with the control group,apoptosis rates of spermatozoa in each sodium arsenite exposure group were higher,and the differences were statistically significant.Conclusion:VEGF may participate in the regulation of testicular function in rats with chronic arsenic poisoning through paracrine-autocrine,and VEGF and VEGFR2 play an important role in the spermatogenesis and development of rats with arsenic poisoning.