PORCINE MODELS OF CORONARY ARTERY DISEASE IN DIABETES

描述(由申请人提供)： 该项目的中心目的是通过内分泌、代谢和心血管标准来表征糖尿病和CAD/再狭窄的猪模型，并为细胞和分子机制的研究提供动物资源。研究人员已经证明，糖尿病脂代谢紊乱(DD)猪会加速冠状动脉粥样硬化，从而使支架植入自然的动脉粥样硬化病变，而不是球囊损伤的健康动脉是可行的。总体假设：糖尿病患者冠状动脉支架置入术后死亡率增加与非支架性冠状动脉病变进展和/或微血管功能障碍有关。总体实验设计：对断奶仔猪进行最佳胆固醇反应筛选，从幼年到成年对糖尿病进行研究。正常对照组(C)、高脂/高胆固醇饲料喂养的高脂血症和动脉粥样硬化组(H)、糖尿病高脂血症和动脉粥样硬化组(DD)分别给予低脂饲料喂养的健康对照组(C)、高脂/高胆固醇饲料喂养的高脂血症和动脉粥样硬化(H)组、糖尿病血脂异常和动脉粥样硬化组(DD)，然后支架植入天然动脉粥样硬化病变，然后恢复。猪模型能够严格控制变量和CAD的侵入性措施，并为体外组织和细胞/分子研究提供充足的血浆和动脉。这一强大的实验设计还使研究未植入支架的动脉中动脉粥样硬化的自然进展成为可能。这些能力在广泛使用的啮齿动物和转基因小鼠模型中是不可能的。具体目标是：1)描述糖尿病的内分泌和代谢指标。在体内，糖耐量和胰岛素敏感性将决定这些模型是否代表1型、2型或IGT形式的糖尿病；2)描述糖尿病血脂异常。传统的空腹血脂(低密度脂蛋白、高密度脂蛋白)和更新的磷脂、脂肪酸和载脂蛋白的特征将描述糖尿病血脂异常的独特特征。脂蛋白进入动脉和对体外细胞增殖的影响将评估动脉粥样硬化。餐后血脂将评估冠状动脉的致动脉环境；3)确定支架内再狭窄是否没有增加；相反，非支架管道的冠心病进展和微血管功能障碍增加。血管内超声将提供体内形态的高空间分辨率，血管内多普勒超声将评估微血管功能障碍，以与无创血管超声和超声心动图进行比较。4)确定冠状动脉结构CAD的范围。组织学将决定导管内膜增厚和生长的程度；相反，微血管预计基本上没有动脉粥样硬化。支架置入区和非支架置入区动脉脂类和脂代谢的高效液相分析将补充IVUS评估。与乳内动脉和外周动脉(臂动脉和股动脉)的比较将是血管异质性的特征；5)为其他研究人员提供这一动物资源。将建立一个组织银行。猪模型的发展为我们未来的几乎所有研究提供了基本的基础，包括药物治疗、其他冠状动脉干预措施的评估、运动训练以及糖尿病CAD/再狭窄的细胞/分子机制的详细研究。

DESCRIPTION (provided by applicant): The central purpose of this project is to characterize porcine models of diabetes and CAD/restenosis by endocrine, metabolic, and cardiovascular criteria and provide this animal resource for studies of cellular and molecular mechanisms. The investigators have shown that Diabetic Dyslipidemic (DD) pigs have accelerated coronary atheroma, thus making it feasible to stent natural atherosclerotic lesions, not balloon-injured healthy arteries. Overall hypothesis: CAD progression in non-stented conduits and/or microvascular dysfunction contribute to the increased mortality after coronary stenting in diabetes. Overall experimental design: Weanling pigs are screened for optimal cholesterol responses and diabetes is studied from juvenile through adult. Pig groups are maintained as low fat fed healthy controls (C), high fat/cholesterol fed hyperlipidemic and atherosclerotic (H), and diabetic dyslipidemic and atherosclerotic (DD), then natural atherosclerotic lesions are stented, followed by recovery. The porcine model enables tight control of variables, invasive measures of CAD, and provides ample plasma and arteries for in vitro tissue and cell/molecular studies. This powerful experimental design also enables the study of natural progression of atherosclerosis in arteries that are not stented. These capabilities are not possible in widely used rodent and transgenic mouse models. Specific Aims are: 1) Describe the endocrine and metabolic indices of diabetes. In vivo glucose tolerance and insulin sensitivity will determine whether these models represent type 1, type 2, or IGT forms of diabetes; 2) Describe diabetic dyslipidemia. Traditional fasting lipids (LDL, HDL) and more novel phospholipid, fatty acid, and ApoB lipoprotein characterization will describe unique features of diabetic dyslipidemia. Uptake of lipoproteins into arteries and effects on cell proliferation in vitro will assess atherogenicity. Postprandial lipids will assess the atherogenic milieu presented to coronary arteries; 3) Determine whether in-stent restenosis is not increased; instead, progression of CAD in non-stented conduits and microvascular dysfunction are increased. Intravascular ultrasound will provide high spatial resolution of in vivo morphology and intravascular Doppler FIoWires will assess microvascular dysfunction for comparison to non-invasive vascular ultrasound and echocardiography. 4) Determine the extent of coronary artery structural CAD. Histology will determine the extent of intimal thickening and growth in conduits; in contrast, microvessels are predicted to be essentially devoid of atheroma. HPLC analysis of artery lipids and lipid metabolism in stented and non-stented regions will complement IVUS evaluation. Comparison to internal mammary artery and peripheral arteries (brachial and femoral) will characterize vascular heterogeneity; and 5) Provide this animal resource to other investigators. A tissue bank will be established. Development of porcine models provides the fundamental basis for virtually all of our future studies, including pharmacotherapy, evaluation of other coronary interventions, exercise training, and detailed studies of cellular/molecular mechanisms of CAD/restenosis in diabetes.