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后的冠状动脉病变(CAD)，以及涉及的冠状动脉平滑肌(CSM)钙信号机制。我们认为非支架导管的冠心病进展和/或微血管功能障碍可能是糖尿病患者冠状动脉支架术后死亡率增加的原因之一。我们已经证明，糖尿病脂代谢紊乱(DD)猪会加速冠状动脉粥样硬化，因此支架植入自然的动脉粥样硬化病变是可行的，而不是球囊损伤的健康动脉。总体假设：运动诱导的钙定位改变是抑制DD患者支架置入后管状CSM的生长和微血管CSM收缩的关键信号。总体实验设计：冠状动脉支架放置在低脂喂养的健康对照组(C)、高脂/胆固醇喂养的高脂血症和动脉粥样硬化(H)、糖尿病血脂异常和动脉粥样硬化(DD)以及接受有氧运动训练的DD猪(DDX)中。具体目的是验证以下假设：与非糖尿病患者(H)相比，DD患者在支架置入后较长时间恢复后：1)支架内再狭窄没有增加；相反，非支架导管的CAD进展和微血管功能障碍增加，并通过运动预防两者。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。2)非支架冠脉病变的进展与运动所阻止的冠脉内皮素和血管生长增加直接相关，而与微血管功能障碍无关。组织学将确定导管内膜增厚的程度和内皮素的含量。冠状动脉脂质的高效液相色谱检测将补充组织学，以确定DD是否比H有更多的细胞损害。3)在非支架管道中，CAD的进展与增加的酪氨酸激酶、CaN和KCA电流直接相关，这些都可以通过运动来预防。单细胞酪氨酸磷酸化、钙库分布和细胞核钙(Ca/n)将用共聚焦显微镜测量。用膜片钳技术测量钙依赖性钾电流(Kca)。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电流的降低可以通过运动来预防。功能性钙释放发生在肌膜上，引起肌膜上的Kca、超极化和松弛，而Kca在DD时减少。本研究的意义在于临床和功能终点(AIMS 1，2)与运动对糖尿病血脂异常的管状和微血管CSM疗效的钙定位机制的差异(AIMS 3，4)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.