PI3K/Akt 信号通路在慢性肾衰竭大鼠肾组织的表达及肾衰Ⅱ号方的干预作用

摘要

目的：研究肾衰Ⅱ号方对于5／6（ablation／ infarction，A／ I）肾切除法制备的慢性肾衰竭大鼠肾功能及 PI3K／ Akt信号通路表达的影响。方法：从 SD 雄性大鼠中随机抽取14只为假手术组（A 组），其余采用5／6（ablation／ infarction，A／ I）肾切除法制备慢性肾衰竭大鼠模型，随机分为模型组（B 组）、西药组（氯沙坦钾＋福辛普利）（C 组）、中药组（肾衰Ⅱ号方）。给予相应干预，60 d 后检测大鼠肾功能[肌酐（Scr）、尿素氮（BUN）]、内生肌酐清除率（Ccr）、血常规（Hb）、左肾重／体重，HE 病理染色观察肾组织形态，Western blot 法检测组织磷酸化 Akt（p - Akt）、总 Akt（pan Akt）蛋白表达。结果：（1）造模手术后，与A 组比较，各手术组的 BUN、Scr 明显升高（P ﹤0．01），Ccr 明显降低（P ﹤0．01），提示造模成功；（2）与 B 组比较，C、D 组 Scr均明显下降（P ﹤0.01，P ﹤0．01）、BUN 水平下降（P ﹤0.05，P ﹤0．01），Ccr、Hb 均明显升高（P ﹤0.01，P ﹤0．01），左肾重／体重降低（P ﹤0．05）；C 组与 D 组比较，在降低 Scr 和 BUN，改善 Ccr 和 Hb，两种药物差异有统计学意义（P ﹤0．05），而在左肾重／体重比值方面两组差别无统计学意义（P ﹥0．05）；干预前后比较，C 组和 D 组治疗前后 Scr、BUN、Ccr 差异有统计学意义（P ﹤0．05），且肾衰Ⅱ号方在降低 Scr、BUN，改善 Ccr 方面优于氯沙坦钾合蒙诺（P ﹤0．05）。（3）肾组织病理显示，两个治疗组病理变化明显减轻，优于模型组。（4）与 B 组比较，两治疗组皮质、髓质 p - Akt／ pan Akt 比值明显降低（P ﹤0.01，P ﹤0．01）；两组间降低 p - Akt／ pan Akt 比值的作用差异有统计学意义（P ﹤0．01），肾衰Ⅱ号方在下调 p - Akt／ pan Akt 比值方面优于氯沙坦钾合蒙诺。结论：肾衰Ⅱ号方可以改善5／6肾切除慢性肾衰竭大鼠的肾脏功能，减轻肾间质纤维化，其作用机制可能是通过下调 PI3K／ Akt 信号通路的表达实现。%Objective:To investigate the effects of“Meliorated Renal Failure Decoction”on the renal functions and the ex-pression of PI3K/ Akt pathway in the remnant nephridial tissue of 5 / 6th kidney ablation/ infarction[5 / 6A/ I])rats. Methods:SD male rats were made into CRF model by means of 5 / 6th kidney ablation/ infarction. The study was divided into sham operation group (Group A),model group(Group B)and Cozaar - with - Monopril group(Group C)and“MRFD”group(Group D),each with 14 rats. Each group was given relevant intervention treatment once daily by administration for 60 successive days. The serum creatinine (Scr),blood urea nitrogen(BUN),and creatinine clearance rate(CCr)were detected. The pathomorphology of the nephridial tissue was observed. The expressions of p - Akt、pan Akt protein in the remnant renal cortex and medulla were assessed by Western blotting analysis. Results:(1)After being modeled,compared with the sham operation group,the levels of SCr and BUN increased(P ﹤0. 01)and the level of CCr decreased(P ﹤ 0. 01)in the operation groups,indicating successful modeling. (2)After intervention treatment,in Group C and D compared with Group B,the level of Scr、BUN decreased(P ﹤ 0. 01,P ﹤ 0. 01),BUN decreased(P ﹤0. 05,P ﹤ 0. 01),Ccr、Hb value increased(P ﹤ 0. 01,P ﹤ 0. 01),and the ratio of left renal weight to body weight came down(P ﹤0. 05). Between Group C and Group D,differences were found existing in the value of Scr、BUN、Ccr、Hb value(P ﹤ 0. 05). Compa-ring the Pre - and - After results of the intervention treatment,differences between Group C and Group D were significant in treating Scr、BUN and Ccr(P ﹤ 0. 05).“MRFD”had better effect in decreasing Scr、BUN and improving Ccr than Cozaar - with - Monopril (P ﹤ 0. 05)but not in improving the ratio of left renal weight to body weight(P ﹥ 0. 05).(3)The pathology of the nephridial tissue showed that the pathological changes in group C and group D were obviously ameliorated,better than those of the model group.(4) Compared with the model group after treatment,the level of protein expression of p - Akt/ pan Akt(P ﹤ 0. 01,P ﹤ 0. 01)in the renaI cortex and the medulla obviously decreased in both group C and group D. The differences between Group C and D were significant (P ﹤ 0. 01),“MRFD”also had better effect in down - regulating the expression of PI3K/ Akt pathway than Cozaar - with - Mono-pril. Conclusion:“MRFD”can improve renal functions in CRF rats induced by 5 / 6(A/ I),which might be associated with improve-ment of renal microcirculation impact of energy metabolism,down - regulation the expressions of PI3K/ AKT signal transduction path-way.