不同年龄对维生素D_3和尼古丁诱导大鼠血管钙化的影响

目的:比较不同年龄大鼠对维生素D3和尼古丁诱导血管钙化的反应性,以利于血管钙化动物模型制备的合理选择。方法:不同月龄大鼠用维生素D3肌肉注射(300 000 IU/kg)和尼古丁灌胃(25 mg/kg)处理后6周,测定各组大鼠颈动脉血压和心功能、血管钙含量及碱性磷酸酶活性;用Von Kossa染色方法检测血管钙沉积;用竞争性半定量逆转录聚合酶链反应方法测定主动脉骨标志蛋白骨桥蛋白(osteopontin,OPN)、骨保护素(osteoprotegerin,OPG)、基质Gla蛋白(matrixGla protein,MGP)、骨形态发生蛋白2(bone morphogenetic protein-2,BMP2)的mRNA水平;用Western blot的方法检测主动脉平滑肌肌动蛋白-α(smooth musule actin-α,α-SMA)水平。结果:2、8和16月龄钙化组大鼠收缩压(systolic blood pressure,SBP)分别升高了20.7%、29.4%和22.2%(P<0.05);左心室收缩末压(left ventricular systolic pressure,LVSP)分别升高13...

Effect of age on vascular calcification induced by vitamine D_3 and nicotine

Obiective:To explore the effect of age on vascular calcification induced by vitamine D_3 and nicotine.Methods:Vascular calcification in rats was induced by adminstration of vitamine D_3 plus nico-tine(VDN treatment).After six weeks,Von Kossa staining,calcium content,alkaline phosphatase ac-tivity,phosphorus and calcium content in plasma were assayed.Carotid blood pressue,cardiac function and the relative amounts of osteopontin(OPN)、osteoprotegerin(OPG)、matrix Gla protein(MGP)、bone morphogenetic protein-2(BMP2) mRNA level and smooth musule actin-α(α-SMA)protein level were measured.Results:Compared with control group,the systolic blood pressure(SBP)of the rats of 2,8 and 16 months with vascular calcification respectively increased by 20.7%,29.4%and 22.2%(P<0.05);the left ventricular systolic pressure(LVSP)respectively increased by 13.6%,21.1% and 16.2%(P<0.05);+LVdP/dt_(max) respectively increased by 49.1%(P<0.01),21.4%and 13.1%(P<0.05);-LVdP/dt_(max) respectively increased by 56.3%(P<0.01),24.4%and 11.3%(P<0.05).Aortic calcium contents of the 2-,8- and 16- month calcified rats were respectively 2.62-fold(P<0.05),24.87-fold(P<0.01)and 10.01-fold(P<0.05)of the age-matched control group.As com-pared with the aortic calcium contents of calcified groups at different ages,the calcification group of 8 months had higher aortic calcium content than those of 2 and 16 months,which were respectively,5.28-fold and 2.63- fold(P<0.05).Compared with the control groups,alkaline phosphatases activity(ALP)of calcification groups increased respectively by 126.6%,115.2%and 227.9%(P<0.01)in the 2-,8- and 16- month rats.As compared with the ALP activity of calcified groups at difierent ages,ALP acti-vity of aortic calcification group of the 8-month-old rats was higher than that of the 2-month-old and 16-month-old rats,which increased by 176%and 75%respectively(all P<0.01).Von kossa staining for calcification showed positive staining as black/brown areas within the main,large,nodular structures as shown in extracellular matrix and cytoplasma in VDN groups at different ages,especially in the 8-month-old VDN group,with the most dispersed calcific nodules deposited and a few of the elastic fibers of the medial layer collapse.The mRNA expressions of OPN,OPG,MGP,BMP,were up-regulated(P<0.01 or P<0.05)and protein levels of α-SMA were down-regulated in difierent calcification groups(P