慢性马兜铃酸肾病大鼠贫血发生的机制

目的 探讨慢性马兜铃酸肾病（CAAN）贫血的发生机制。 方法 用62只SD大鼠筛查血红蛋白（Hb），求正常值。随机选择24只Hb正常的大鼠，分为对照组及模型组，各12只，后者予关木通浸膏水溶液间断灌胃制作CAAN模型。在给药前及8周末，分别检测两组各6只大鼠体质量、Hb、尿蛋白量（24 h）及肌酐清除率（Ccr），然后处死大鼠，留取肾组织做Masson染色观察肾间质纤维化程度；实时定量PCR法检测肾组织中红细胞生成素（EPO）mRNA表达；免疫组化染色观察肾组织中Ⅰ型胶原（ColⅠ）、氨基肽酶P（APP）、低氧诱导因子（HIF）1α及2α的蛋白表达。 结果 大鼠的正常Hb值为（155.9±16.5） g/L，低于123.6 g/L为贫血。给药前，对照组与模型组间各指标的差异均无统计学意义。8周末时，与对照组比较，模型组大鼠Hb和Ccr显著下降[（121.66±15.68） g/L比（169.00±12.89） g/L，（0.63±0.13） ml/min比（1.27±0.18） ml/min]；尿蛋白量（24 h）显著增多[（27.04±9.40） mg/d比（6.11±0.84） mg/d]；肾间质纤维化相对面积及ColⅠ相对面积显著增加[（12.89±2.33）%比（0.55±0.10）%，（13.92±2.92）%比（1.32±0.84）%]；肾组织APP蛋白表达和EPO mRNA表达显著下调 [（0.55±0.23）%比（3.77±1.06）%，0.005±0.001比0.032±0.013]；HIF-1α和HIF-2α蛋白表达显著上调 （2.55±0.16比1.12±0.46，2.33±0.33比1.15±0.27）（均P < 0.01）。 结论 CAAN的贫血发生可能与肾小管周毛细血管毁坏所导致的EPO产生减少有关，虽然HIF表达已代偿性增强，但仍未能阻止贫血发生。

Pathogenesis of anemia in chronic aristolochic acid nephropathy rats

Objective To study the pathogenesis of anemia in chronic aristolochic acid nephmpathy(CAAN) rats. Methods The hemoglobin(Hb)values of sixty-two male SD rats were assayed to determine its normal range.Among them,24 rats with normal Hb value were randomly divided into 2 groups:model group (MG)in which rats received the extract of Aristololochia manshuriensis Kom (AmK) by gavage,and control group (CG) received tap water only by gavage.Body weisht(BW),Hb,24 h urinary protein excretion(UP)and creatinine clearance (Ccr)of 6 rats in each group were measured before administration and at the end of the 8th week, respeetively.then these rats were sacrificed.The relative area of renal interstitial fibrosis was measured by microscopy.The mRNA expression of erythropoietin (EPO)in kidney tissue Was determined by real-time RT-PCR;protein expression of type I collagen(Coll),aminopeptidase P (APP),hypoxia indHeible factor let and 2α(HIF-1α and HIF-2α)in kidney tissue Was examined by immunohistochemistry staining. Results Hb values of normal rats presented normal distribution. The normal Hb was (155.9±16.5) g/L. Rat anemia was diagnosed when Hb was below 123.6 g/L. There was no difference in all the examination results between CG and MG before administration (P>0.05). Compared with CG, the Hb and Cer in MG were significantly decreased [(121.66±15.68) g/L vs (169.00±12.89) g/L, (0.63±0.13) ml/min vs (1.27±0.18) ml/min, P< 0.01], and the UP in MG was significantly increased at the end of the 8th week [(27.04±9.40) mg/d vs (6.11±0.84) mg/d, P<0.01]; the relative areas of fibrosis and Col l in renal interstitium of MG were significantly enlarged [(12.89±2.33)% vs (0.55±0.10)%, (13.92±2.92)% vs (1.32±0.84)%, P<0.01]; the protein expression of APP and the mRNA expression of EPO in the kidney tissue of MG were significantly down-regulated [(0.55±0.23)% vs (3.77±1.06)%, 0.005±0.001 vs 0.032±0.013, P<0.01]; the protein expression of HIF-lα and HIF-2α in the kidney tissue of MG was significantly up-regulated (2.55±0.16 vs 1.12±0.46, 2.33±0.33 vs 1.15±0.27, P<0.01), at the end of the 8th week. Conclusions The pathogenesis of anemia in CAAN may be due to the decreased production of EPO caused by the destruction of peritubular capillary. The compensatory up-regulation of HIF-lα and HIF-2α expression can not prevent the anemia development.