ACEI对去卵巢骨质疏松大鼠激肽释放酶-激肽系统及骨丢失的影响

Effect of ACEI on kallikrein-kinin system and bone loss in ovariectomized osteoporotic rats

目的探究血管紧张素转换酶抑制剂(angiotensin-converting enzyme inhibitor,ACEI)卡托普利对去卵巢(OVX)骨质疏松大鼠骨丢失及激肽释放酶-激肽(kallikrein-kinin system,KKS)系统的影响。方法去卵巢法制备绝经骨质疏松大鼠模型,分为OVX组、ACEI组[6 mg/(kg·d)卡托普利]、阳性对照雌激素组[0.05 mg/(kg·d)己烯雌酚],另不去卵巢为Sham组。给药8周后,全自动生化分析仪检测血清钙(Ca)、Ⅰ型前胶原N-端肽(PINP)、碱性磷酸酶(ALP)、骨钙素(OCN)、抗酒石酸酸性磷酸酶(TRAP)及Ⅰ型胶原交联C端肽β序列(β-CTX)水平,微型计算机断层摄影术(micro CT)法检测骨密度及微结构,TRAP法观察骨组织破骨细胞数量,Western blot法检测骨组织中骨形态发生蛋白2(BMP2)、Runt相关转录因子2(Runx2)、组织激肽释放酶(KLK)、缓激肽受体1(B1R)及缓激肽(BK)蛋白表达。结果相较于Sham组,OVX组大鼠骨密度、骨小梁数量及厚度、骨体积分数、SMI、PINP、ALP、OCN水平、BMP2、Runx2蛋白表达均降低(P均<0.05),骨小梁分离度、TRAP、β-CTX水平、破骨细胞数量、KLK、B1R及BK蛋白水平均增加(P均<0.05)。相较于OVX组,ACEI组、阳性组大鼠骨密度、骨小梁数量及厚度、骨体积分数、SMI、PINP、ALP、OCN水平、BMP2、Runx2蛋白表达均增加,骨小梁分离度、TRAP、β-CTX水平、破骨细胞数量、KLK、B1R及BK蛋白水平降低(P<0.05)。结论 ACEI可抑制KKS系统,降低破骨细胞活性减少骨吸收,增强成骨细胞活性增加骨形成,提高骨密度,改善骨微结构,进而改善OVX大鼠骨质疏松症状。

Objective To investigate the effect of angiotensin-converting enzyme inhibitor( ACEI) captopril on bone loss and kallikrein-kinin system( KKS) in ovariectomized( OVX) osteoporotic rats. Methods Postmenopausal osteoporosis rat model was established using ovariectomy. The rats were divided into OVX group,ACEI group( 6 mg/kg. d captopril),positive control estrogen group( 0. 05 mg/kg. d diethylstilbestrol),and sham group without ovariectomy. After 8 weeks of administration,the levels of serum calcium( CA),procollagen I N-terminal peptide( PINP),alkaline phosphatase( ALP),osteocalcin( OCN),tartrate resistant acid phosphatase( TRAP),and C-terminal telopeptides of type I collagen( β-CTX) were detected with automatic biochemical analyzer.Bone mineral density and microstructure were measured with micro CT. The number of osteoclasts was measured with TRAP method.The protein expressions of bone morphogenetic protein 2( BMP2),Runt related transcription factor 2( Runx2),kalli-krein( KLK),bradykinin receptor 1( B1 R) and bradykinin( BK) were detected with Western blotting. Results Compared with those in sham group,BMD,number and thickness of trabeculae,bone volume fraction,SMI,PINP,ALP,OCN levels,BMP2 and Runx2 protein expressions were significantly lower in OVX group( all P < 0. 05),and trabecular separation,TRAP,and β-CTX levels,osteoclast number,KLK,B1 R,and BK protein levels were higher( all P < 0. 05). Compared with those in OVX group,BMD,number and thickness of trabeculae,bone volume fraction,SMI,PINP,ALP,and OCN levels,BMP2 and Runx2 protein expressions were significantly higher in ACEI group and positive group( all P < 0. 05),and trabecular separation,TRAP and β-CTX levels,osteoclast number,KLK,B1 R,and BK protein levels were lower( P < 0. 05). Conclusion ACEI inhibits KKS system,reduces osteoclast activity,reduces bone resorption,enhances osteoblast activity,increases bone formation,increases bone mineral density,improves bone microstructure,and relieves osteoporosis symptoms in OVX rats.