EXERCISE, DIABETES, AND CORONARY SMOOTH MUSCLE CALCIUM

运动、糖尿病和冠状动脉平滑肌钙

• 批准号: 6537584
• 负责人: Michael Sturek
• 金额: $ 37.35万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6537584
• 关键词: atherosclerotic plaque; blood chemistry; blood glucose; blood lipid; calcium channel; calcium flux; coronary artery; coronary disorder; diabetes mellitus; dietary lipid; disease /disorder model; endothelin; exercise; histology; hormone receptor; nonhuman therapy evaluation; sarcoplasmic reticulum; swine; ultrasound blood flow measurement; vascular smooth muscle; vasomotion

Our long-term goal is to determine if exercise training attenuates the excess coronary artery disease (CAD) in diabetes and the vascular smooth muscle (VSM) Ca (Cam) signaling mechanisms involved. In our porcine model of diabetic dyslipidemia coronary arteries show increases in contraction to prostaglandin F2alpha (PGF) and Cam responses to endothelin-1 (ET). Exercise of normal swine decreases Ca release from the sarcoplasmic reticulum (SR) and increases Ca influx, while decreasing ET-induced contraction and DNA synthesis. However, ET-induced contraction does not require Ca release that is dependent on tyrosine kinase, a signal for cell growth. Overall hypothesis: after exercise training increased ET-induced Ca influx attenuates contraction, while decreased SR Ca release attenuates growth of smooth muscle. Design: low fat control pigs (C), high fat fed (HF), and alloxan diabetic and high fat fed (D) pigs are maintained for 20 and 30 wk to study the progression of CAD and compared to D pigs exercise trained (D plus EX). Specific Aims are to test the hypotheses that in diabetes: 1) Exercise improves glycemic and lipidemic status. Diabetes will be defined by measures of blood glucose, glycated protein, insulin, etc. HDL, LDL, VLDL, triglycerides, apoproteins, glycated LDL, and ET will define features of diabetic dyslipidemia. 2) Exercise attenuates the increase in CAD. Intravascular ultrasound will assess atheroma and vasoconstrictor responses to PGF and ET in vivo. Histology and contractile tension responses of coronary rings to PGF and ET will provide in vitro measures of CAD. 3) Exercise attenuates the conversion of VSM from the contractile (cVSM) to synthetic (sVSM) phenotype. sVSM cell phenotype will be identified using digital imaging microscopy by the Cam response to UTP, perinuclear SR, DNA, smooth muscle actin, desmin, and vimentin. 4) Exercise attenuates the increased contraction of cVSM by increasing ET receptor-dependent Ca influx. Mn and Ba influx used as Ca surrogates will assess Ca influx. Subsarcolemmal Ca localization relative to ryanodine receptors will be digitally imaged. 5) Exercise attenuates the increased ET-induced Cam amplitude and nuclear Ca localization by decreasing tyrosine kinase-dependent Ca release from the SR. Imaging will assay in single cells the relative content and spatial distribution of ET, ryanodine, and IP3 receptors, tyrosine phosphorylation, DNA and Cam. Significance: the first study of Ca localization mechanisms involved in the excess CAD in diabetic dyslipidemia and the therapeutic effects of exercise on CAD.

我们的长期目标是确定运动训练是否可以减轻糖尿病患者的过度冠状动脉疾病 (CAD) 以及相关的血管平滑肌 (VSM) Ca (Cam) 信号传导机制。 在我们的糖尿病血脂异常猪模型中，冠状动脉显示出对前列腺素 F2α (PGF) 的收缩增加以及对内皮素-1 (ET) 的 Cam 反应。 正常猪的运动会减少肌浆网 (SR) 的 Ca 释放并增加 Ca 内流，同时减少 ET 诱导的收缩和 DNA 合成。 然而，ET 诱导的收缩不需要 Ca 释放，而 Ca 释放依赖于酪氨酸激酶（细胞生长的信号）。 总体假设：运动训练后，ET 诱导的 Ca 内流增加会减弱收缩，而 SR Ca 释放减少会减弱平滑肌的生长。 设计：将低脂肪对照猪 (C)、高脂肪饲喂猪 (HF) 以及四氧嘧啶糖尿病和高脂肪饲喂猪 (D) 饲养 20 周和 30 周，以研究 CAD 的进展情况，并与经过运动训练的 D 猪进行比较 (D)加上 EX）。具体目的是测试糖尿病中的假设：1) 运动改善血糖和血脂状态。 糖尿病将通过血糖、糖化蛋白、胰岛素等指标来定义。HDL、LDL、VLDL、甘油三酯、脱辅基蛋白、糖化LDL和ET将定义糖尿病血脂异常的特征。 2) 运动可减弱 CAD 的增加。血管内超声将评估体内动脉粥样硬化和血管收缩剂对 PGF 和 ET 的反应。 冠状动脉环对 PGF 和 ET 的组织学和收缩张力反应将提供 CAD 的体外测量。 3) 运动减弱 VSM 从收缩性 (cVSM) 到合成性 (sVSM) 表型的转化。 sVSM 细胞表型将使用数字成像显微镜通过 Cam 对 UTP、核周 SR、DNA、平滑肌肌动蛋白、结蛋白和波形蛋白的反应来识别。 4) 运动通过增加 ET 受体依赖性 Ca 流入来减弱 cVSM 的收缩增加。 用作 Ca 替代物的 Mn 和 Ba 流入量将评估 Ca 流入量。 肌膜下 Ca 相对于兰尼碱受体的定位将被数字成像。 5) 运动通过减少 SR 酪氨酸激酶依赖性 Ca 释放来减弱 ET 诱导的 Cam 振幅和核 Ca 定位的增加。 成像将测定单细胞中 ET、兰尼定和 IP3 受体、酪氨酸磷酸化、DNA 和 Cam 的相对含量和空间分布。意义：首次研究了糖尿病血脂异常中过量 CAD 涉及的 Ca 定位机制以及运动对 CAD 的治疗作用。