PORCINE MODELS OF CORONARY ARTERY DISEASE IN DIABETES

描述（由申请人提供）： 本项目的主要目的是通过内分泌、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这种动物资源。 研究人员已经表明，糖尿病血脂异常（DD）猪加速了冠状动脉粥样硬化，从而使支架植入自然动脉粥样硬化病变，而不是球囊损伤的健康动脉成为可能。 总体假设：非支架导管中的CAD进展和/或微血管功能障碍导致糖尿病患者冠状动脉支架植入术后死亡率增加。 总体实验设计：筛选断奶仔猪的最佳胆固醇反应，并从幼年至成年研究糖尿病。 将猪组维持为低脂肪喂养的健康对照（C）、高脂肪/胆固醇喂养的高血脂和动脉粥样硬化（H）以及糖尿病血脂异常和动脉粥样硬化（DD），然后对天然动脉粥样硬化病变进行支架植入，然后恢复。 猪模型能够严格控制变量，CAD的侵入性测量，并为体外组织和细胞/分子研究提供充足的血浆和动脉。 这种强大的实验设计也使研究动脉粥样硬化的自然进展，没有支架。 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。具体目的是：1）描述糖尿病的内分泌和代谢指标。 体内葡萄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（LDL，HDL）和更新颖的磷脂，脂肪酸和载脂蛋白B脂蛋白表征将描述糖尿病血脂异常的独特特征。 动脉对脂蛋白的摄取和对体外细胞增殖的影响将评估动脉粥样硬化的发生。 餐后血脂将评估冠状动脉的致动脉粥样硬化环境; 3）确定支架内再狭窄是否没有增加;相反，非支架导管中CAD的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FIoWire将评估微血管功能障碍，以与非侵入性血管超声和超声心动图进行比较。4)确定冠状动脉结构性CAD的范围。 组织学将确定内膜增厚和导管生长的程度;相反，微血管预计基本上没有粥样硬化。 支架植入和非支架植入区域的动脉脂质和脂质代谢的HPLC分析将补充IVUS评价。 与乳内动脉和外周动脉（肱动脉和股动脉）的比较将表征血管异质性;以及5）将该动物资源提供给其他研究者。 将建立组织库。 猪模型的开发为我们未来几乎所有的研究提供了基本基础，包括药物治疗、其他冠状动脉介入治疗的评价、运动训练和糖尿病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.