纤溶酶原激活物/Ⅰ型纤溶酶原激活物抑制物的失衡在大鼠肾脏衰老过程中的意义

目的　探讨纤溶酶原激活物 (PAs)及其抑制物 1(PAI 1)在大鼠肾脏衰老过程中的作用。方法　选用 3、12、2 4个月龄Wistar大鼠 ,采用免疫组化技术分别检测组织型纤溶酶原激活物 (t PA)、尿激酶型纤溶酶原激活物 (u PA)、PAI 1及转化生长因子 β1(TGF β1)在不同年龄大鼠肾组织中的表达。 结果　PAI 1主要表达在肾小球壁层上皮细胞、内皮细胞及系膜细胞、小血管的内皮细胞及平滑肌细胞和肾小管上皮细胞 ,并随增龄表达增强 (P <0 0 1) ;t PA主要表达在肾小球、肾小管 ,并随增龄表达减弱 (P <0 0 1) ;u PA主要表达在肾小管上皮细胞 ,亦随增龄表达减弱 (P <0 0 1) ;TGF β1主要表达在肾小球、血管周围、小管及间质 ,随增龄表达增强 (P <0 0 1)。PAI 1与TGF β1与肾小球硬化有相关性 (P <0 0 5 )。结论　PA/PAI 1表达失衡在肾脏衰老过程中可能起重要作用

THE SIGNIFICANCE OF IMBALANCE BETWEEN PLASMINOGEN ACTIVATORS AND PLASMINOGEN ACTIVATOR INHIBITOR-1 DURING THE PROCESS OF AGING IN KIDNEY OF RATS

Objective To investigate the expression and role of plasmi no gen activators (PAs) and plasminogen activator inhibitor-1(PAI-1) in the aging process of rats kidney. Methods Immunohistochemical assays w ere applied to detect the expression of tissue-type plasminogen activator (t-P A), urokinase-type plasminogen activator (u-PA), PAI-1 and transforming growt h factor-β1 (TGF-β1) in renal tissue of rats. The rats were divided into 3 g roups (n=8): three-month-old group (3 months), twelve-month-old group (1 2 months) and twenty four-month-old group (24 months). Results PAI-1 was detected, at a low level, in the tubular epithelial cells and ves sel walls of 3 months and 12 months rats. The expression of PAI-1 was signinifi cantly increased in the glomerular parietal epitheial, mesangial, and endothelia l cells, small vessel endothelial and smooth muscle cells (P<0.01). T-PA was detected in the glomerular and tubular epithelial cells of 3 months and 12 m onths rats. the expression of t-PA was signinificantly decreased in renal tissu e of 24 months rats (P<0.01). U-PA was expressed in the tubular epithelia l cells of 3 months and 12 mrats. The expression of u-PA was signinificantly de creased in renal tissue of 24 months rats (P<0.01). TGF-β1 was only slightly expressed in the tubular epithelial cells, periglomerular and perivascular region of 3 months and 12 months rats. The expression of T GF-β1 was increased notably in glomerulus, tubulointerstitium and per ivascular regions (P<0.01). The expression of PAI-1 and TGF-β1 had posi tive correlations with glomerulosclerosis (P<0.05). Conclusions The imbalance between plasminogen activators and plasminogen activator inhibitor-1 may play an important role during the process of aging in kidney of rats.