EXERCISE, DIABETES, & CORONARY SMOOTH MUSCLE Ca2+

描述（由申请人提供）：该项目的长期目标是确定运动训练在多大程度上降低糖尿病患者支架植入术后冠状动脉疾病（CAD）的发病率，以及所涉及的冠状动脉平滑肌（CSM） Ca信号传导机制。我们认为非支架导管的CAD进展和/或微血管功能障碍可能导致糖尿病患者冠状动脉支架植入术后死亡率增加。我们的研究表明，糖尿病性血脂异常（DD）猪会加速冠状动脉粥样硬化，因此可以对自然动脉粥样硬化病变进行支架治疗，而不是对球囊损伤的健康动脉进行支架治疗。总体假设：运动引起的钙定位改变是减弱DD支架植入后导管CSM生长增加和微血管CSM收缩的关键信号。总体实验设计：将冠状动脉支架放置在低脂肪喂养的健康对照组(C)、高脂肪/胆固醇喂养的高脂血症和动脉粥样硬化(H)、糖尿病性血脂异常和动脉粥样硬化（DD）和有氧运动训练（DDX）的DD猪中。具体目的是检验DD患者与非糖尿病患者(H)相比，支架植入术后较长时间恢复后的假设：1)支架内再狭窄没有增加；相反，非支架患者的冠心病进展和微血管功能障碍增加，两者都可以通过运动预防。血管内超声将提供体内形态的高空间分辨率，血管内多普勒超声线将评估微血管功能障碍。2)冠心病在非支架导管内的进展与冠状动脉内皮素和平滑肌生长的增加直接相关，而非微血管功能障碍，而运动可以预防这些变化。组织学将决定导管内内膜增厚的程度和内皮素含量。HPLC测量冠状动脉脂质将补充组织学，以确定DD是否比h有更多的细胞病变。3)非支架导管中CAD的进展与酪氨酸激酶的增加直接相关。和Kca电流，这些都可以通过运动来预防。用共聚焦显微镜测量单细胞酪氨酸磷酸化、钙储存分布和核钙（Ca/n）。钙依赖的K电流（Kca）将用膜片钳测量。4)微血管功能障碍不涉及Can的改变，但与Kca电流的降低直接相关，而Kca电流的降低可通过运动预防。功能性钙释放在肌膜引起C的Kca、超极化和舒张，而Kca在DD降低。本研究的意义在于运动对糖尿病血脂异常的导管与微血管CSM的治疗效果的临床终点和功能终点（Aims 1,2）与钙定位机制（Aims 3,4）的差异之间的关系。

DESCRIPTION (provided by applicant): The long-term goal of this project is to determine the extent to which exercise training decreases coronary artery disease (CAD) after stenting in diabetes and the coronary smooth muscle (CSM) Ca signaling mechanisms involved. We propose that CAD progression in non-stented conduits and/or microvascular dysfunction may contribute to the increased mortality after coronary stenting in diabetes. We 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: exercise-induced change in Ca localization is a pivotal signal to attenuate increased growth of conduit CSM and contraction of microvascular CSM after stenting in DD. Overall experimental design: coronary stents are placed in low fat fed healthy controls (C), high fat/cholesterol fed hyperlipidemic and atherosclerotic (H), diabetic dyslipidemic and atherosclerotic (DD), and DD pigs that are aerobically exercise trained (DDX). Specific Aims are to test the hypotheses that in DD, compared to non-diabetics (H), after Iong-ter m recovery from stenting: 1) In-stent restenosis is not increased; instead, progression of CAD in non-stented cohduits and microvascular dysfunction are increased and both are prevented by exercise. Intravascular ultrasound will provide high spatial resolution of in vivo morphology and intravascular Doppler FIoWires will assess microvascular dysfunction. 2) Progression of CAD in non-stented conduits, but not microvascular dysfunction, is directly related to increased coronary endothelin and smooth muscle growth, which are prevented by exercise. Histology will determine the extent of intimal thickening and endothelin content in conduits. HPLC measures of coronary artery lipids will complement histology to determine whether DD have more cellular lesions than H. 3) Progression of CAD in non-stented conduits is directly related to increased tyrosine kinase, Can., and Kca current, which are prevented by exercise. Single cell tyrosine phosphorylation, distribution of Ca stores, and nuclear Ca (Ca/n) will be measured with confocal microscopy. Ca-dependent K currents (Kca) will be measured with patch clamp. 4) Microvascular dysfunction involves no change in Can, but is directly related to decreased Kca current, which is prevented by exercise. Functional Ca release is at the sarcolemma eliciting Kca, hyperpolarization, and relaxation in C, while Kca decreases in DD. Significance of this research is the relation of clinical and functional endpoints (Aims 1,2) to the differences in Ca localization mechanisms (Aims 3,4) of the therapeutic effects of exercise on conduit vs. microvascular CSM in diabetic dyslipidemia.