放疗对前尿道狭窄模型兔iNOs和MMP-2的影响  

The irradiation impact on the expression of iNOs and MMP-2 in rabbit model of anterior urethral stricture

作　　者：周克斌[1] 赵留存[1] 杨勇[1] 杨京可[1] 虎威 屈卫星[2] 

机构地区：[1]西安交通大学附属西安市第九医院泌尿外科,陕西西安710061 [2]西安交通大学医学院第三附属医院泌尿外科,陕西西安710068

出　　处：《现代泌尿外科杂志》2012年第1期32-35,共4页Journal of Modern Urology

摘　　要：目的建立前尿道狭窄模型兔动物模型,研究局部放疗对尿道移行上皮下的结缔组织中与瘢痕修复密切相关的组织型一氧化氮合酶(iNOs)基质金属蛋白酶2(MMP-2)表达的影响。方法建立电刀灼热伤所致的前尿道狭窄兔动物模型,随机分为放疗2周组,放疗4周组和未放疗组。当灼热伤后,在尿道内镜下可见到灼伤处黏膜苍白,周围血管扩张时,放疗组应用铱192γ射线对灼伤处上下0.5cm进行内照射,1.25Gy/次,隔日一次,共5Gy/次。当放疗结束后两周,同时处死放疗组,未放疗组兔。将前尿道狭窄段及上下0.5cm进行取材;当放疗结束后4周,同时处死放疗组,未放疗组兔。将前尿道狭窄段及上下0.5cm进行取材。免疫组化法检测尿道移行上皮下的组织中组织型一氧化氮合酶(iNOs)和基质金属蛋白酶2(MMP-2)表达。结果 2周和4周的取材标本中,放疗组的iNOs和较未放疗组表达降低(P<0.05);而基质金属蛋白酶(MMP-2)较未放疗组表达增强(P<0.05)。结论放疗增强了前尿道狭窄兔动物模型尿道组织中基质金属蛋白酶(MMP-2)的表达;降低了组织型一氧化氮合酶(iNOs)的表达,为临床联合运用冷刀尿道瘢痕切开术后于早期安全剂量的放疗以及细胞因子靶向治疗,预防尿道狭窄复发提供了实验依据。Objective To establish rabbit model of anterior urethral stricture and to study the impact of local radiotherapy on the expression of nitric oxide synthase（iNOs） matrix metalloproteinase 2（MMP-2）.Methods After rabbit models of anterior urethral stricture caused by electric knife burning wounds were established,they were divided randomly into 2-week radiotherapy group and non-radiotherapy group,4-week radiotherapy group and non-radiotherapy group.When the rabbits were wounded by burning,the lesion was pale under urinary tract endoscope,and peripheral vascular expanded,in the radiotherapy groups,the burned lesions were irradiated by Iridium192γ ray for 1.25 Gy once every other day,5 Gys in total.2 and 4 weeks after the radiotherapy,all rabbits were killed.The urethral samples were taken from the anterior urethral stricture（0.5cm）.The expression of nitric oxide synthase（iNOs） and matrix metalloproteinase 2（MMP-2） on endepidermis in the urinary tract was then detected with immunohistochemical method.Results In the 2-week and 4-week samples,the expression of iNOs in the radiotherapy groups reduced sharply（P0.05） while the expression of matrix metalloproteinase（MMP-2） increased significantly（P0.05） compared with those in the non-radiotherapy groups.Conclusion Radiotherapy enhances matrix metalloproteinase（MMP-2） expression in the rabbit model of anterior urethral stricture and reduces tissue nitric oxide synthase（iNOs） expression,which provides experimental evidence for the combined use of cold knife for urethral scar incision,early postoperative safe dose radiation and cytokine targeting treatment,and the prevention of recurrent urethral stricture.

关 键 词：放射治疗 尿道狭窄 组织型一氧化氮合酶 基质金属蛋白酶2 动物模型 

分 类 号：R69[医药卫生—泌尿科学]