氨基胍对糖尿病大鼠肾组织中糖化终产物受体mRNA表达的调节

目的研究氨基胍对糖尿病肾组织内糖化终产物（ＡＧＥｓ）受体（ＲＡＧＥ）ｍＲＮＡ表达的影响。方法采用逆转录聚合酶链式反应（ＲＴＰＣＲ）检测病程８周肾内ＲＡＧＥｍＲＮＡ水平。结果诱发糖尿病４周后糖尿病大鼠肾皮、髓质内ＲＡＧＥｍＲＮＡ表达增加（Ｐ＜０．０５）,８周时更为明显（Ｐ＜０．０５）;口服补充氨基胍４周对肾内这种改变未产生影响（Ｐ＞０．０５）,给药８周,糖尿病大鼠肾皮、髓质内增强的ＲＡＧＥｍＲＮＡ表达明显缓解（Ｐ＜０．０５）。与此同时,氨基胍在不影响血糖的基础上,使糖尿病大鼠升高的糖化血红蛋白（ＧＨｂ）水平下降２６．７２％。结论糖尿病状态下,肾组织内ＲＡＧＥｍＲＮＡ高表达可能是高血糖诱发ＡＧＥｓ形成的结果;氨基胍可通过调节ＲＡＧＥｍＲＮＡ的异常表达,缓解ＡＧＥｓ对肾组织的损伤。     

橙皮苷与氨基胍对STZ－糖尿病大鼠主动脉胶原非酶糖化作用的比较

本文观察了天然黄酮类化合物──橙皮苷对ＳＴＺ－糖尿病大鼠主动脉胶原非酶糖基化作用的影响，并与氨基肌进行了比较。结果表明：用橙皮苷及氨基肌治疗１２０天后，糖尿病鼠动脉胶原ＡＧＥｓ含量明显降低（Ｐ＜０．０１），而血糖、体重无明显差别。提示橙皮苷对糖尿病大鼠蛋白非酶糖基化作用与氨基胍相似。     

晚期糖化终产物对糖尿病大鼠肾小球改变的影响

目的 探讨晚期糖化终产物（ＡＧＥｓ）与糖尿病肾小球改变的关系。方法 用链脲佐菌素制糖尿病大鼠模型，观察肾小球ＡＧＥｓ、血小板源生长因子－Ａ（ＰＤＧＦ－Ａ）和超微结构的变化。结果 肾小球ＡＧＥｓ从４周起、ＰＤＧＦ－Ａ从８周起增多，１２周时，基膜增厚，系膜增宽。氨基胍能降低ＡＧＥｓ含量，减缓肾小球改变。结论 ＡＧＥｓ是肾小球改变的重要原因，其致病过程可能有ＰＤＧＦ－Ａ参与。     

水飞蓟宾、槲皮素对糖尿病鼠主动脉胶原和血清β脂蛋白非酶糖化的阻断作用

中药用于糖尿病及其并发症的预防和治疗的确切机理尚不清楚。本文发现链脲菌素引起的糖尿病大鼠模型，８周后主动脉胶原（ａｄｖａｎｃｅｄｇｌｙｃｏｓｙｌａｔｉｏｎｅｎｄｐｒｏｄｕｃｔｓ，ＡＧＥ）荧光强度、胶原含量、糖化血清β脂蛋白（β－Ｌｐ）均明显增加，Ｐ＜０．０１。分别给予水飞蓟宾、槲皮素１００ｍｇ·ｋｇ－１／ｄ，治疗８周后，发现血糖无明显降低。而大鼠主动脉胶原及胶原ＡＧＥ含量、血清糖化β－Ｌｐ含量均有明显降低并接近正常。揭示水飞蓟宾、槲皮素对动物组织蛋白的非酶糖化有明显的抑制作用     

阻断肾内肾素-血管紧张素系统对转化生长因子β1mRNA及细胞外基质表达的作用

目的探讨苯那普利延缓肾脏疾病进展的可能作用机制。方法采用实验性肾小球硬化模型,治疗组给苯那普利（４ｍｇ·ｋｇ－１·ｄ－１）。用比色法和放免法分别测定肾内血管紧张素转换酶（ＡＣＥ）活性和血管紧张素Ⅱ（ＡｎｇⅡ）含量,免疫组化检测肾组织转化生长因子β１（ＴＧＦβ１）和细胞外基质（ＥＣＭ）,原位杂交观察ＴＧＦβ１ｍＲＮＡ表达。结果治疗组肾内ＡＣＥ活性和ＡｎｇⅡ与非治疗组比较,受到明显抑制（Ｐ＜０．０１）。治疗组肾小球和肾小管区ＴＧＦβ１ｍＲＮＡ表达量显著低于非治疗组（Ｐ＜００１）。同时,ＥＣＭ在肾小球内沉积也较非治疗组显著减少（Ｐ＜０．０１）。结论苯那普利通过阻断肾内肾素血管紧张素系统,在下调ＴＧＦβ１表达和ＥＣＭ积聚中起重要作用。     

维生素E对不同病程糖尿病鼠主动脉胶原非酶糖化的影响

为探讨维生素Ｅ对非酶糖化的影响，本研究观察了糖尿病大鼠喂饲维生素Ｅ后主动脉胶原Ａｍａｄｏｒｉ产物、高级糖基化终末产物（ＡＧＥｓ）、ＡＧＥｓ—交联量及胶原含量的改变，发现喂饲维生素Ｅ的病鼠与相应年龄未喂饲维生素Ｅ的病鼠相比，其主动脉胶原Ａｍａｄｏｒｉ产物、ＡＧＥｓ、ＡＧＥｓ—交联量、胶原含量均明显下降，且治疗时间越长、疗效越明显，但均未能达到正常水平。说明维生素Ｅ能够抑制糖尿病患鼠主动脉胶原发生非酶糖化和棕色变，能增强胶原的可溶性，减少胶原在血管壁基底膜的沉积，从而可能有利于延缓糖尿病慢性血管病变的发生和发展     

糖尿病大鼠糖化终产物与主动脉壁细胞间粘附分子—1关系的 …

目的 了解糖尿病大鼠体内糖化终产物（ＡＧＥＳ）的产生与主动脉壁细胞间粘附分－１（ＩＣＡＭ－１）表达的并在体外确定ＡＧＥＳ是否具有独立致内皮细胞ＩＣＡＭ－１表达的作用。方法将糖尿病大鼠（ＤＭ组）、糖尿病氨基胍治疗大鼠（ＡＧ组）和正常大鼠（Ｃ组）分别喂是１、２、３、４个月后，其Ｈｂ－ＡＧＥｓ含量有主动脉壁ＩＣＡＭ－１表达情况。用流式细胞仪在半定量ＥＬＩＳＡ检测培养的内皮细胞ＡＧＥＳ作用后ＩＣＡＭ－１生     

氨基胍对非酶糖基化人脐静脉内皮细胞信号转导物DAG影响

目的： 为探讨氨基胍（ＡＧ）对非酶糖化（ＮＧＥｓ）引起的人脐静脉内皮细胞信号（ＤＡＧ）转导的影响及其机制。方法：采用薄层层析、放射自显影及放射酶标法分离、检测细胞中ＤＡＧ含量,应用荧光法检测ＮＧＥｓ的含量。结果：氨基胍组荧光值从２７．８±５．９（ＡＦＵ）降为８．５±２．８（ＡＦＵ） ,ＤＡＧ含量从５４１．５±４６．２３ ｐｍ ｏｌ·Ｌ－ １ 降为２５３．５±１８．２０ ｐｍ ｏｌ·Ｌ－ １。结论：氨基胍明显阻断糖基化终末产物（ＮＧＥｓ）的形成,并且由ＮＧＥｓ刺激内皮细胞产生的ＤＡＧ含量显著降低。这对糖尿病的慢性并发症防止提供了重要的理论依据     

转化生长因子β1在超压力负荷肥厚心肌中的表达及Losar …

本研究旨在探讨转化生长因子β１（ＴＧＦ－β１）在左室肥厚发生、发展中的作用及与血管紧张素Ⅱ（ＡｎｇⅡ）关系,以及Ｌｏｓａｒｔａｎ对左室肥厚的干预作用。应用放射免疫分析法及免疫组化方法测定腹主动脉缩窄后心肌组织ＡｎｇⅡ水平、ＴＧＰ－β１的表达变化。发现腹主动脉缩窄后心肌组织ＡｎｇⅡ水平及血管紧张素转换酶（ＡＣＥ）活性升高（Ｐ〈０．０１）,ＴＧＦ－β１在心肌细胞浆中的表达显著增加（Ｐ〈０．０１）,术后     

碱性成纤维细胞生长因子在低氧性肺动脉高压大鼠肺内表达及分布变化的观察

目的探讨碱性成纤维细胞生长因子（ｂＦＧＦ）在慢性低氧性肺动脉高压中的作用。方法建立慢性低氧性肺动脉高压大鼠模型，测定肺血流动力学及肺小动脉显微形态计量学，用免疫组化方法观察ｂＦＧＦ在大鼠肺组织的表达和分布。结果缺氧组大鼠平均肺动脉压（ｍＰＡＰ）、肺小动脉壁厚度占血管外径的百分比（ＭＴ％）分别为３．９６±０．４７ｋＰａ、３４±４％，明显高于对照组（Ｐ＜０．０１）；肺小动脉壁ｂＦＧＦ染色明显强于对照组（Ｐ＜０．０１），并和ＭＴ％呈正相关。结论（１）慢性缺氧能导致肺小动脉重建及肺动脉高压。（２）ｂＦＧＦ参与了慢性低氧性肺动脉高压肺血管重建的调控。     

Exogenous advanced glycosylation end products induce complex vascular dysfunction in normal animals: a model for diabetic and aging complications.

Advanced glycosylation end products (AGEs) have been implicated in many of the complications of diabetes and normal aging. Markedly elevated vascular tissue and circulating AGEs were linked recently to the accelerated vasculopathy of end-stage diabetic renal disease. To determine the pathogenic role of AGEs in vivo, AGE-modified albumin was administered to healthy nondiabetic rats and rabbits alone or in combination with the AGE-crosslink inhibitor aminoguanidine. Within 2-4 weeks of AGE treatment, the AGE content of aortic tissue samples rose to six times the amount found in controls (P < 0.001). Cotreatment with aminoguanidine limited tissue AGE accumulation to levels two times that of control. AGE administration was associated with a significant increase in vascular permeability, as assessed by 125I label tracer methods. This alteration was absent in animals that received aminoguanidine in addition to AGE. Significant mononuclear cell migratory activity was observed in subendothelial and periarteriolar spaces in various tissues from AGE-treated rats compared to normal cellularity noted in tissues from animals treated with aminoguanidine. Blood pressure studies of AGE-treated rats and rabbits revealed markedly defective vasodilatory responses to acetylcholine and nitroglycerin compared to controls (P < 0.001), consistent with marked NO. inactivation; aminoguanidine treatment significantly prevented this defect. These in vivo data demonstrate directly that AGEs, independent of metabolic or genetic factors, can induce complex vascular alterations resembling those seen in diabetes or aging. AGE administration represents an animal model system for the study of diabetic and aging complications as well as for assessing the efficacy of newly emerging therapies aimed at inhibiting advanced glycosylation.     

槲皮素对糖尿病大鼠主动脉胶原非酶糖化的抑制作用

观察了槲皮素（Qu）对不同病程糖尿病（DM）大鼠主动脉胶原非酶糖化的抑制作用，并与氨基胍（AG）作对比。结果：Qu（100mg·kg-1／d）灌胃治疗9周，能明显抑制主动脉胶原及胶原交联的AGEs含量，与等剂量AG作用相近，但起效要晚。Qu有一定的降压作用，但对血糖及血清果糖胺无影响。提示Qu能通过抑制胶原非酶糖化来防治DM血管病变。     

Attenuation of hypertension development by aminoguanidine in spontaneously hypertensive rats: role of methylglyoxal

BACKGROUND: Methylglyoxal (MG), a metabolite of glucose, and MG-induced advanced glycation endproducts (AGEs) are causatively associated with vascular complications of diabetes mellitus. We have previously reported elevated levels of MG and MG-induced AGEs in spontaneously hypertensive rats (SHR). The purpose of this study was to investigate the causative role of MG and MG-induced AGEs in the pathogenesis of hypertension in SHR. METHODS: Young SHR were treated with an AGE inhibitor, aminoguanidine, for 9 weeks. HPLC was used to determine plasma and aortic MG and reduced glutathione levels. The MG-induced AGEs, N epsilon-carboxyethyl-lysine (CEL) and argpyramidine, in the aorta were determined by immunohistochemistry. Vascular relaxation of small mesenteric arteries was measured using myograph. RESULTS: Chronic treatment with aminoguanidine attenuated age-dependent blood pressure (BP) increase in SHR. Plasma and aortic MG levels, and aortic levels of MG-induced AGEs, were significantly reduced after aminoguanidine treatment, which were comparable to those from age-matched Wistar Kyoto rats. Free radical level was significantly lowered, whereas reduced glutathione level was significantly increased by aminoguanidine treatment in the aortic tissues from SHR. Moreover, aminoguanidine therapy prevented the morphologic damage of vascular tissues in SHR and restored the endothelium-dependent relaxation to acetylcholine. Chronic aminoguanidine treatment also increased aortic endothelial nitric oxide synthase expression and reduced inducible nitric oxide synthase expression. CONCLUSIONS: The MG and MG-induced AGEs contribute to the pathogenesis of hypertension by altering the redox balance, causing vascular eutrophic inward remodeling, and inducing endothelial dysfunction in SHR.     

晚期糖基化终末产物对糖尿病大鼠主动脉结构和功能的影响

目的探讨晚期糖基化终末产物(AGEs)对主动脉血管结构和功能影响及氨基胍的保护作用。方法将80只雄性SD大鼠随机分为4组:空白对照组(A组),糖尿病组(B组),糖尿病氨基胍干预组(C组)和空白氨基胍干预组(D组),每组20只。药物应用12周观察主动脉功能和结构变化。结果与A组和D组比较,B组、C组主动脉环对去甲肾上腺素引起的收缩反应明显增强,对乙酰胆碱引起的舒张反应则均明显减弱,C组反应强度较B组明显减轻(P0.05,P0.01)。主动脉壁均有AGEs沉积,B组、C组较明显,C组较B组明显减轻(P0.01);超微结构观察显示,A组、D组主动脉内膜大致正常,B组、C组内膜破坏明显,与动脉环结果呈一致性趋势。结论糖尿病大鼠主动脉AGEs含量增多,损伤了主动脉的结构和功能,氨基胍能够减少AGEs的沉积,并对主动脉结构和功能有保护作用。     

橙皮苷对STZ糖尿病大鼠肾脏功能和形态的影响

观察橙皮苷对链脲佐菌素导致的糖尿病大鼠肾脏功能和形态的影响,并与氨基胍进行比较。结果表明:（1）两治疗组大鼠尿蛋白排泄量显著低于对照组P<0.05）;（2）两治疗组肾组织AGEs和LPO含量显著低于对照组（P<0.01,P<0.05）:（3）治疗组肾小球系膜增生和基底膜增厚明显减轻。提示橙皮苷在抑制蛋白非酶糖基化、预防糖尿病肾脏并发症方面具有与氨基胍相似的作用。     

Role of profilin-1 in vasculopathy induced by advanced glycation end products (AGEs)

AimsTo construct a simple and feasible rat model to mimic diabetic vasculopathy by chronic injection of advanced glycation end products (AGEs) and further determine the role of profilin-1 in vasculopathy in AGE-injection rats.MethodsSprague-Dawley rats were injected with AGEs-BSA (25 mg/kg/day) for 0, 20, 30, 40, and 60 days by caudal vein. Then, the morphological changes in the aorta, heart, and kidney and the expression of profilin-1 were assessed. In cultured endothelial cells, shRNA profilin-1 was used to clarify the role of profilin-1 in AGEs-induced vascular endothelial lesions and inflammatory reactions.ResultsThe aorta, heart, and kidney of the AGE-injection rats had obvious morphological changes. Also, the indicators of vascular remodeling in the aorta significantly increased, accompanied by the increased expression of profilin-1 in the aorta, heart, and kidney and polysaccharide content on the kidney basement membrane. In addition, the protein level of profilin-1 was markedly upregulated in the aorta of AGEs-injected rats and endothelial cells incubated with AGEs. shRNA profilin-1 markedly attenuated the upregulated expression of profilin-1, receptor for AGEs (RAGE), and NF-κB in endothelial cells incubated with AGEs, as well as reduced the high levels of ICAM-1, IL-8, TNF-α, ROS, and apoptosis induced by AGEs.ConclusionsExogenous AGEs can mimic diabetic vasculopathy in vivo to some extent and increase profilin-1 expression in the target organs of diabetic complications. Blockade of profilin-1 attenuates vascular lesions and inflammatory reactions, suggesting its critical role in the metabolic memory mediated by AGEs.     

吡哆胺和替米沙坦对大鼠腹主动脉平滑肌细胞增生、凋亡及血清糖基化终末产物的影响

目的 观察应用吡哆胺和替米沙坦对自发性高血压大鼠(SHR)腹主动脉平滑肌细胞增生、凋亡和血清糖基化终末产物(AGE)、活性氧(SOD)的影响,探讨血管重塑的可能机制.方法 选取22周龄雄性SHR,随机分为高血压对照组(n=12)、替米沙坦组(n=12)、吡哆胺组(n=12)、替米沙坦与吡哆胺联合治疗组(联合治疗组,n=12)和正常对照组(n=12).测定各实验组大鼠的血压,ELISA法检测血清AGE,化学发光法测定一氧化氮(NO)、SOD,免疫组化法测定增殖细胞核抗原和凋亡指数.HE染色观察各组实验动物腹主动脉形态学变化.结果 替米沙坦组和联合治疗组的收缩压均明显低于高血压对照组(P均<0.01),而吡哆胺组无明显改变(P>0.05).替米沙坦组、吡哆胺组和联合治疗组血清NO和SOD水平均显著高于高血压对照组(P均<0.01),而且联合治疗组明显高于两个单药治疗组(P均<0.05).替米沙坦组、吡哆胺组和联合治疗组血清AGE水平均显著低于高血压对照组(P均<0.01),而且联合治疗组明显低于两个单药治疗组(P均<0.05).腹主动脉HE染色形态学观察显示替米沙坦组、吡哆胺组和联合治疗组血管平滑肌细胞的排列、增生,血管壁内膜完整性,弹力板受压和胶原纤维增生情况均明显优于高血压对照组.替米沙坦组、吡哆胺组及联合治疗组增殖细胞核抗原的表达均显著低于高血压对照组(P均<0.01),且联合治疗组更低于各单药干预组(P均<0.05).替米沙坦组、吡哆胺组和联合治疗组细胞凋亡指数均显著高于高血压对照组(P均<0.01),联合治疗组干预后的细胞凋亡指数高于两个单药治疗组(P均<0.05).结论 吡哆胺和替米沙坦可部分协同改善SHR腹主动脉的血管重构,可能与抑制氧化应激和AGE生成,抑制细胞增生核抗原和调节细胞凋亡有关.

Abstract：

Objective To investigate the effects of telmisartan and pyridoxamine on vascular smooth muscle cells (VSMCs) proliferation and apoptosis as well as abdominal aorta vascular remodeling in spontaneously hypertensive rats (SHRs). Methods SHRs randomly received placebo, telmisartan(6 mg*kg-1*d-1), pyridoxamine(200 mg*kg-1*d-1) or telmisartan (6 mg*kg-1*d-1) plus pyridoxamine (200 mg*kg-1*d-1, n=12 each) for 16 weeks. Wistar-Kyoto (WKY, n=12) rats serve as normotensive contro1. The systolic blood pressure (SBP) of rat was measured before and weekly thereafter. The serum advanced glycation end-products (AGEs) were detected by competitive ELISA. The serum super oxide dismutase (SOD) and nitric oxide (NO) were measured. The abdominal aorta were assessed by image analysis in HE stained sections. The VSMCs apoptosis and proliferation in abdominal aorta were detected with in situ end labeling technique and proliferating cell nuclear antigen (PCNA) immunohistoehemistry staining respectively. Results SBP were significantly lower in telmisartan and telmisartan plus pyridoxamine therapy group than in placebo treated hypertensive rats while not affected by pyridoxamine (P>0.05). Activity of SOD and NO were significantly higher and AGEs significantly lower in telmisartan, pyridoxamine and combination therapy treated SHRs than in placebo treated hypertensive rats(P<0.01). The elmisartan, pyridoxamine and combination therapy can significantly inhibit the PCNA expression and significantly enhance the apoptosis value in abdominal aorta(P<0.01). The efficacy of combined treatment was significantly higher than telmisartan and pyridoxamine alone(P<0.05). Conclusion Telmisartan and pyridoxamine could attenuate abdominal aorta vascular remodeling via reducing oxidative stress and AGEs production as well as restoring the balance of VSMCs proliferation and apoptosis in SHRs abdominal aorta.     

Evidence against the involvement of nonenzymatic glycosylation in diabetic cardiomyopathy

There is evidence to suggest that increased nonenzymatic glycosylation (NEG) occurs in hyperglycemic states such as seen in diabetes mellitus. In order to examine the hypothesis that the development of cardiomyopathy in diabetes results from an increased nonenzymatic glycosylation of cardiac sarcolemmal proteins, rats were made diabetic by an intravenous (IV) injection of streptozotocin (65 mg/kg). Twelve weeks after the induction of diabetes, animal showed significantly lower heart rate, left ventricular systolic pressure, rate of contraction (+dp/dt), and rate of relaxation (-dp/dt), whereas left ventricular diastolic pressure was markedly increased. Furthermore, cardiac sarcolemmal Na+, K+ adenosine triphosphatase (ATPase) activity was significantly decreased in diabetic rats. When examined in cardiac crude membranes, as well as in purified sarcolemmal membranes prepared by two different procedures, the levels of NEG did not differ between control and diabetic animals; however, NEG levels were increased in kidney and skeletal muscle. These results indicate that chronic diabetes is associated with functional and biochemical alterations in cardiac muscle and suggest that NEG of cardiac sarcolemma may not play any role in the development of diabetic cardiomyopathy.     

Lipoprotein Modification by Advanced Glycosylation Endproducts (AGEs): Role in Atherosclerosis

Recent progress in our understanding of advanced glycosylation reactions in vivo has affirmed the hypothesis that these products play an important role in the evolution of both diabetic and nondiabetic vascular disease. Utilizing newly developed advanced glycosylation end-products (AGE)-specific enzyme-linked immunosorbent assay (ELISA) techniques, AGEs have been identified to be present on a variety of vascular wall, lipoprotein, and lipid constituents. Vascular wall AGEs contribute to vascular pathology by increasing vascular permeability, enhancing subintimal protein and lipoprotein deposition, and inactivating nitric oxide. Lipid-linked AGEs present in low-density lipoprotein (LDL) also have been shown to initiate oxidative modification, promoting oxidation reactions that may proceed without the involvement of free metals or other radical generating systems. AGE-specific ELISA analysis has demonstrated a significantly increased level of AGE-modified LDL in the plasma of diabetic patients when compared to normal controls. AGE-modification impairs LDL-receptor-mediated clearance mechanisms in vivo and may contribute to elevated LDL levels in patients with diabetes. This concept has been substantiated further by the recent clinical observations that administration of the advanced glycosylation inhibitor aminoguanidine to diabetic patients significantly decreases circulating LDL levels. (Trends Cardiovasc Med 1997;7:39-47). ? 1997, Elsevier Science Inc.