【摘要】 目的：探讨血管紧张素（1-7）[Ang (1-7)]对大鼠尿毒症高转性骨病的影响，并阐明其可能的机制。方法：30只SD大鼠随机分为假手术组（n=6）和实验组（n=24），实验组大鼠采用5/6肾切除术（Platt法）+高磷（P）饮食[1.2%P,1.0%钙（Ca）]制备尿毒症高转化骨病模型，并将建模成功的大鼠随机分为模型组、Ang (1-7)组、血管紧张素转换酶2 (ACE2)激活剂二乙酰胺三氮脒（DIZE）组（DIZE组）和Mas受体拮抗剂组（A779组），每组6只。分别于手术后12和18周采用全自动生化分析仪检测各组大鼠血清Ca、P、血肌酐（Scr）、血尿素氮（BUN）和24 h尿蛋白（UP）水平；免疫化学荧光法测定各组大鼠全段甲状旁腺素（iPTH）水平；酶联免疫吸附试验（ELISA）法检测各组大鼠血清骨钙素（OC）、Ⅰ型胶原N端肽（NTX）和抗酒石酸酸性磷酸酶（TRAP）-5b水平；高分辨率显微CT扫描检测各组大鼠股骨组织的骨密度（BMD）、组织骨密度（TMD）、骨小梁厚度（Tb. Th）和骨小梁分离度（Tb. Sp）等三维结构参数。Von Kossa染色和吉姆萨染色观察各组大鼠皮质骨及骨小梁病理形态表现，计算骨小梁体积（TBV）；荧光显微镜下测定各组大鼠骨矿化率（MAR），并计算成骨细胞指数（OBI）和破骨细胞指数（OCI）。结果：术后12和18周，与假手术组比较，模型组、Ang (1-7)组、DIZE组和A779组大鼠体质量减小（P<0.05）；术后12和18周，与假手术组比较，模型组、Ang (1-7)组、DIZE组和A779组大鼠血清中24 h UP、Scr及BUN水平均升高（P<0.05）；术后18周，与模型组比较，Ang (1-7)组和DIZE组大鼠血清中24 h UP及Scr水平均降低（P<0.05）,A779组大鼠血清中24 h UP、Scr和BUN水平均升高（P<0.05）。证实尿毒症高转化骨病大鼠模型构建成功。术后12和18周，与假手术组比较，模型组、Ang (1-7)组、DIZE组和A779组大鼠血清中iPTH、P、OC、NTX及TRAP-5b水平均升高（P<0.05）；术后18周，与模型组比较，Ang (1-7)组和DIZE组大鼠血清中NTX及TRAP-5b水平均降低（P<0.05）, A779组大鼠血清中iPTH、 P、 NTX和TRAP-5b水平均升高（P<0.05）。高分辨率显微CT扫描检测，与假手术组比较，模型组、Ang (1-7)组、DIZE组和A779组大鼠股骨BMD及TMD均降低（P<0.05）；与模型组比较，Ang (1-7)组和DIZE组大鼠股骨BMD及TMD均升高（P<0.05）,A779组大鼠股骨BMD和TMD均降低（P<0.05）。与假手术组比较，模型组大鼠股骨Tb. Th降低（P<0.05）,Tb. Sp升高（P<0.05）;Ang (1-7)组和DIZE组大鼠股骨Tb. Th升高（P<0.05），而Tb. Sp降低（P<0.05）；与模型组比较，A779组大鼠股骨Tb. Th降低（P<0.05），而Tb. Sp升高（P<0.05）。骨病理检查，与假手术组比较，模型组、Ang(1-7)组、DIZE组和A779组大鼠股骨TBV均降低（P<0.05）,MAR、OBI和OCI均升高（P<0.05）；与模型组比较，Ang (1-7)组和DIZE组大鼠股骨OBI及OCI均降低（P<0.05）,TBV升高（P<0.05），而A779组大鼠股骨OBI和OCI均升高（P<0.05）,TBV降低（P<0.05）。结论：ACE2/Ang(1-7)/Mas轴对尿毒症大鼠高转化骨病具有改善作用。更多还原

【Abstract】 Objective:To discuss the effect of angiotensin(1-7) [Ang(1-7)] on high-turnover bone disease in the uremic rats, and to clarify its possible mechanism. Methods: Thirty SD rats were randomly divided into sham operation group(n=6) and experimental group(n=24). The rats in experimental group underwent 5/6 nephrectomy(Platt method) + high-phosphorus(P) diet[1. 2% P, 1. 0% calcium(Ca)] to establish the model of uremic high-turnover bone disease. The successfully modeled rats were then randomly divided into model group, Ang(1-7) group, angiotensin-converting enzyme 2(ACE2) activator dimethylacetamide amidoxime(DIZE) group, and Mas receptor antagonist group(A779 group), with 6 rats in each group. The levels of Ca, P, blood creatinine(Scr), blood urea nitrogen(BUN), and 24 h urinary protein(UP) in serum of the rats in various groups were detected by automatic biochemical analyzer at 12 and 18 weeks after operation; immunofluorescence staining was used to detect the levels of intact parathyroid hormone(iPTH) in the rats in various groups; ELISA method was used to detect the levels of osteocalcin(OC), type Ⅰ collagen N-terminal peptide(NTX), and tartrate-resistant acid phosphatase(TRAP)-5b in serum of the rats in various groups; high-resolution micro-CT scan was used to detect the bone density(BMD), tissue mineral density(TMD), trabecular thickness(Tb.Th), and trabecular separation(Tb. Sp) in femur tissue of the rats in various groups; Von Kossa staining and Giemsa staining were used to observe the pathomorphology of cortical bone and trabecular bone of the rats in various groups, and the trabecular bone volume(TBV) was calculated; fluorescence microscope was used to detect the mineral apposition rates(MAR) of the rats in vanious groups, and the osteoblast index(OBI) and osteoclast index(OCI) of the rats in various groups were calculated. Results: At 12 and 18 weeks after operation, compared with sham operation group, the weights of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were decreased(P<0. 05). At 12 and 18 weeks after operation, compared with sham operation group, the levels of 24 h UP, Scr, and BUN in serum of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were increased(P<0. 05); at 18weeks after operation, compared with model group, the levels of 24 h UP and Scr in serum of the rats in Ang(1-7) group and DIZZ group were decreased(P<0. 05), and the levels of 24 h UP, Scr and BUN in serum of the rats in A779 group were increased(P<0. 05). The successful establishment of the uremic high-turnover bone disease model was confirmed. At 12 and 18 weeks after operation, compared with sham operation group, the serum iPTH, P, OC, NTX, and TRAP-5b levels of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were all significantly increased(P<0. 05); at 18 weeks after operation, compared with model group, the serum NTX and TRAP-5b levels of the rats in Ang(1-7) group and DIZE group were decreased(P<0. 05), while the serum iPTH, P, NTX and TRAP-5b levels in A779 group were increased(P<0. 05). The high-resolution micro-CT scan results showed that compared with sham operation group, the values of femur BMD and TMD of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were all significantly decreased(P<0. 05); compared with model group, the values of femur BMD and TMD of the rats in Ang(1-7) group and DIZE group were increased(P<0. 05), while the values of BMD and TMD of the rats in A779 group were decreased(P<0. 05). Compared with sham operation group, the femur Tb. Th of the rats in model group was decreased(P<0. 05), and the Tb. Sp was increased(P<0. 05); the femur Tb. Th of the rats in Ang(1-7) group and DIZE group were increased(P<0. 05), and the Tb. Sp was decreased(P<0. 05). Compared with model group, the femur Tb. Th of the rats in A779 group was decreased(P<0. 05), and the Tb. Sp was increased(P<0. 05).The bone pathological examination results showed that compared with sham operation group, the femur TBV of the rats in model group, Ang(1-7) group, DIZZ group and A779 group were decreased(P<0. 05), and MAR, OBI and OCI were increased(P<0. 05); compared with model group, the OBI and OCI of the rats in Ang(1-7) group and DIZE group were decreased(P<0. 05), and TBV was increased(P<0. 05), while the OBI and OCI of the rats in A779 group were increased(P<0. 05), and TBV was decreased(P<0. 05). Conclusion: The ACE2/Ang(1-7)/Mas axis improves high-turnover bone disease in the uremic rats.更多还原