神经源性膀胱组织中一氧化氮合酶表达的特点和意义

目的 探讨神经元型一氧化氮合酶(nNOS)、诱导型NOS(iNOS)和内皮型NOS(eNOS)在神经源性膀胱组织中表达状况,探讨一氧化氮在神经源性膀胱组织中产生及作用特点.方法 神经源性膀胱患儿30例.男18例,女12例.年龄(6.3±3.1)岁.30例均行手术治疗,术中留取膀胱组织标本,采用免疫组织化学方法检测膀胱组织中nNOS、iNOS和eNOS表达状况,10例正常膀胱组织标本作对照. 结果 正常膀胱体部组织nNOS阳性表达,走行在平滑肌纤维之间,分布于平滑肌细胞表面,膀胱基质也有表达,组织化学评分(HS)为2.8～4.0和1.2～2.7;平滑肌细胞iNOS阴性表达,平滑肌细胞基质有少量稀疏表达,HS为0～0.4和0～0.1;eNOS表达分布于血管内皮细胞中,分布稀疏,平滑肌细胞无表达.膀胱颈部组织表达高于膀胱体部组织,以nNOS表达为主.神经源性膀胱组织中以iNOS表达为主,nNOS表达明显减少;eNOS主要分布于膀胱基质的内皮细胞,膀胱平滑肌、成纤维细胞阴性表达;病变膀胱组织血管稀疏,微血管密度100倍视野下可见到(6.8±3.2)个血管灶,低于正常膀胱组织的(16.7±6.3)个(P＜0.01).结论 正常膀胱组织nNOS主要分布在膀胱颈中,NO合成主要受nNOS调节.神经源性膀胱患者膀胱组织中氮能神经元分布稀疏,nNOS表达减少,iNOS表达上调,NO的合成与调节可能主要来源于iNOS,受iNOS水平调节,eNOS表达下降,提示膀胱组织血供不良.

Biological significance of expression of nitric oxide synthases in neurogenic bladder

Objective To explore the expression of nitric oxide synthases including neuronal nitric oxide synthases(nNOS), inducible nitric oxide synthases(iNOS), endothelial nitric oxide synthases (eNOS) in neurogenic bladder tissues, and analyze it's producing feature and significance. Methods There were 30 cases with neurogenic bladder(18 males, 12 females). The average age was 6.3±3.1 years. All patients appeared with myelodysplasia, urinary and fecal incontinence in different degree. Twenty-six cases were manifested with hyperreflexia bladders, and all patients were treated with surgical procedures. During operation, collected bladder tissue samples including tissues of apex vesicae and tissues of bladder neck, and all tissues were enveloped with mineral wax. All tissues were detected for nNOS, iNOS, and eNOS respectively in tissues of apex vesicae and tissues of bladder neck,and with normal bladder tissues as control group (bladder tissues of hypospadia, 10 cases), and according to clinical features, to explore the expression of NOS, and to analyze the relationship among them. Results In normal apex vesicae tissues, all cases stained with nNOS, and distributed among bundles of smooth muscles, and surface of smooth muscles and interstitial tissue, histochemica;score (HS) 2.8-4.0 and 1.2-2.7. There were no stained cells in bladder tissues of iNOS, and HS was very low, HS:0-0. 4 and 0-0.1 ;eNOS mainly distributed in interstitial tissues in rarefaction manners, and mainly in vascular endothelial cell (VEC), and smooth muscles had no stainings the most expression among them was nNOS, and mainly distributed in bladder neck tissues. In neurogenic bladder tissues, the main expression of NOS type was iNOS, and nNOS decreased significantly. eNOS mainly expressed in VEC among interstitial tissues, and had no staining in smooth muscle cells and collagenoblast and rarefaction of microvessel in bladder tissues, and microvessel density decreased significantly than normal bladder tissues. Microvessal density(MVD) in bladder tisssus (6. 8± 3.2/100per square) was less than that in normal tissues (16.7±6.3/100 per square). Conclusions In normal bladder tissues, nNOS mainly distributes in bladder neck and urethra, and nitric oxide mainly derives from nNOS. Much more matrix fibers, fewer nitrogenergic nerves, and less nNOS expression are seen in neurogenic bladder interstitial tissue. There are more iNOS expressions in bladder tissues,and NO is mainly derived from iNOS, and it may play an important role in pathological bladder tissues, especially in fibrosis of bladder wall. eNOS may be considered as angiopoietic labeling, and may evaluate the blood supply of bladder.