EXERCISE, DIABETES, AND CORONARY SMOOTH MUSCLE CALCIUM

我们的长期目标是确定运动训练是否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，冠状动脉显示对前列腺素F2 α（PGF）的收缩增加和对内皮素-1（ET）的Cam反应增加。 正常猪运动后肌浆网Ca释放减少，Ca内流增加，ET引起的收缩和DNA合成减少。 然而，ET诱导的收缩不需要依赖于酪氨酸激酶（细胞生长的信号）的Ca释放。 总体假设：运动训练后ET诱导的Ca内流增加，收缩减弱，而SR Ca释放减少，平滑肌生长减弱。 设计图：将低脂肪对照猪（C）、高脂肪饲养的（HF）和四氧嘧啶糖尿病和高脂肪饲养的（D）猪饲养20和30周以研究CAD的进展，并与运动训练的D猪（D + EX）进行比较。具体目的是检验糖尿病的假设：1）运动改善血糖和血脂状态。 通过测量血糖、糖化蛋白、胰岛素等来定义糖尿病。HDL、LDL、VLDL、甘油三酯、载脂蛋白、糖化LDL和ET将定义糖尿病血脂异常的特征。 2)运动可以减弱CAD的增加。血管内超声将评估动脉粥样硬化和血管收缩反应PGF和ET在体内。 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)运动减弱了VSM从收缩型（cVSM）向合成型（sVSM）表型的转化。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鉴定sVSM细胞表型。 4)运动通过增加ET受体依赖性Ca内流来减弱cVSM的收缩增加。 用作Ca替代物的Mn和Ba流入将评估Ca流入。 将对相对于ryanodine受体的肌膜下Ca定位进行数字成像。 5)运动减弱ET诱导的凸轮幅度和核钙本地化减少酪氨酸激酶依赖的钙释放SR。成像将测定在单细胞中的相对含量和空间分布的ET，ryanodine，和IP 3受体，酪氨酸磷酸化，DNA和凸轮。重要性：首次研究了糖尿病血脂异常中过量CAD的钙定位机制以及运动对CAD的治疗作用。

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.