VASCULAR METABOLISM AND ITS RELATION TO FUNCTION

血管平滑肌(VSM)的收缩能力，这是调节的基础 循环，与新陈代谢密切相关。我们已经证明了VSM 新陈代谢在功能上是分区的，即氧化代谢是 与力量密切相关，而有氧糖酵解是独立的 与钠泵相关。我们的中心假设是，观察到的 功能区隔是胞浆的反映 VSM中代谢的区隔。对这一假说的检验和 它对VSM能量学的意义，代谢与 功能，特别是对我们对 VSM代谢的控制，构成了这项工作的基础。第一大调 目的是阐明糖酵解的区隔和 糖原分解。我们的研究将包括确定 糖原中14C的代谢去向和糖酵解的比活性 中间体及其调控机制。这些研究将 引发更广泛的问题，即底物的性质(S) 氧化代谢及其对功能的依赖。这将是 通过测量氧气消耗和二氧化碳产生来解决 建立呼吸商，以及，从各种不同的14C的命运 底物。第二个主要的具体目标涉及澄清 功能性隔间。钠泵耦合的机理 人们对有氧糖酵解知之甚少。我们的假设是，这是 偶联反应了糖酵解酶级联在细胞上的定位 质膜与Na~+-K~+-ATPase紧密结合。这将会被测试 通过对钠泵功能和有氧酵解的定量，首先在完整的 血管，利用K+电极连续监测钠泵功能 乳酸的高分辨率荧光测量。这将进一步 通过细胞分离研究进行测试，包括：定位和 主要氧化酶和糖酵解酶的定量，特别是， 纯化质膜制剂中的糖酵解酶；以及 该细胞组分中钠泵活性和糖酵解的定量。这个 最后一个主要的具体目标涉及阐明控制机制。 为了协调新陈代谢与VSM功能，检验假设 环核苷酸和高能磷酸盐都可能是新陈代谢 监管机构被划分为不同的部门。研究将包括以下方面的相关性 CAMP依赖的蛋白激酶活性与功能性 这些酶的区隔、定位、作用的测定 CAMP在协调糖酵解和钠泵功能中的作用 膜，以及组织磷原和组织磷的等电泳法测量 不同功能负荷条件下的代谢物。冠脉和 颈动脉将是长期目标研究的主要血管。 将新陈代谢与正常的VSM功能联系起来，以便检测和 描述血管疾病的潜在机制。

Vascular smooth muscle (VSM) contractility, which underlies the regulation of circulation, is closely coupled to metabolism. We have shown that VSM metabolism is functionally compartmentalized, i.e., oxidative metabolism is strongly correlated with force whereas aerobic glycolysis is independently correlated with the Na-pump. Our central hypothesis is that this observed functional compartmentation is a reflection of the cytosolic compartmentation of metabolism in VSM. The testing of this hypothesis and its implications for VSM energetics, the coupling of metabolism with function and in particular, to our understanding of the mechanisms for control of VSM metabolism, forms the basis of this work. The first major goal is the elucidation of the compartmentation of glycolysis and glycogenolysis. Our studies will involve the determination of the metabolic fate of 14C from glycogen, the specific activities of glycolytic intermediates, and the mechanisms of its regulation. These studies will lead to the broader question of the nature of the substrate(s) for oxidative metabolism and its dependence on function. This will be addressed by measurement of oxygen consumption and CO2 production to establish the respiratory quotient, and, of the fate of 14C from various substrates. The second major specific aim involves elucidation of the functional compartmentation. The mechanism for the coupling of the Na-pump and aerobic glycolysis is poorly understood. Our hypothesis is that this coupling reflects the localization of a glycolytic enzyme cascade on the plasmalemma in close apposition to the Na+-K+ ATPase. This will be tested by quantitation of Na-pump function and aerobic glycolysis first in intact vessels, utilizing K+-electrodes to continuously monitor Na-pump function and high resolution fluorometric measurement of lactate. This will further be tested by cell fractionation studies including: localization and quantitation of the major oxidative and glycolytic enzymes, particularly, glycolytic enzymes in a purified plasma membrane preparation; and quantitation of Na-pump activity and glycolysis in this cell fraction. The last major specific aim involves the elucidation of the control mechanisms for coordination of metabolism with VSM function, testing the hypothesis that cyclic nucleotides and high energy phosphates, both likely metabolic regulators, are compartmentalized. Studies will include the correlation of the activities of cAMP-dependent protein kinases with the functional compartmentation, localization of these enzymes, determination of the role of cAMP in coordinating glycolysis and Na-pump function in purified plasma membranes, and isotachophoretic measurement of the tissue phosphagen and metabolites under various functional loading conditions. Coronary and carotid arteries will be the major vessels studied with the long term goal of relating metabolism to normal VSM function in order to detect and characterize the mechanisms underlying vascular disease.