Circulating endocannabinoids in rats: Assay development and validation

调节食物摄入量的机制对生存和健康至关重要。虽然食物太少 消费可以导致死亡，21世纪美国面临的一个同等或更大的问题是过度消费 卡路里密集和摄入维生素丰富的食物，导致肥胖和营养不良。CB1 大脑中的大麻素受体(CB1R)在调节食物摄入量方面发挥着至关重要的作用，而激活 外周组织中的CB1R导致脂肪和糖原储存增加；通过 肌肉；棕色脂肪产热减少。内源性大麻素存在于人体内。 循环及其浓度受代谢状态的调节，呈昼夜节律。这些 以前的发现使我们得出了循环中内源性大麻素传递信息的总体假设。 关于需要额外的卡路里摄入，以及持续的高内源性大麻素浓度有助于 为了暴饮暴食。这项提案的目标是建立和描述一种检测系统，在该系统中 测定清醒、自由活动大鼠循环中的内源性大麻素浓度。我们会 检查内源性大麻素浓度在每日周期中的变化；以及以下急性食物 限制和应激，因为这些都被证明影响循环中内源性大麻素的浓度 人类。我们将落实三个具体目标。第一个目标是优化内源性大麻素的测定。 在大鼠血浆中；确定检测和定量的限度，以及稳健性。第二个目标是 应用该方法测定大鼠血液循环内大麻素浓度的昼夜变化 与其他代谢信号分子的关系；以及检查短暂的食物时期的影响 剥夺。第三个目标是研究引起恐惧的气味呈现对 循环中的内源性大麻素。这些研究的圆满完成将为今后的研究奠定基础。 包括探索能量状态变化影响体内内源性大麻素的机制。 循环；循环中内源性大麻素的组织来源；最重要的是， 从循环进入大脑的内源性大麻素将有关代谢状态的信息传递给大脑 奖励巡回活动。这些研究对人类具有高度的可译性，因为内源性大麻素 人体血液中的浓度很容易测量。确实，这个项目的创新之处在于它的 将人类的观察转化为易于进行机械学研究的动物模型。 这个项目的研究将增加我们对几个重要的过程的理解 循环内大麻素浓度，并将为未来的人类和动物研究其 在进食障碍、药物成瘾和情绪障碍中的作用。

The mechanisms that regulate the intake of food are vital for survival and health. While too little food consumption can lead to death, an equal or greater problem in 21st century America is the over-consumption of calorie-dense and inadequate consumption of vitamin-rich foods, resulting in obesity and poor nutrition. CB1 cannabinoid receptors (CB1R) in the brain play a vital role in the regulation of food intake, while activation of CB1R in peripheral tissues results in increased fat and glycogen storage; reduced glucose utilization by muscles; and reduced thermogenesis in brown adipose. Endocannabinoids are present in the human circulation and their concentrations are regulated by metabolic state and exhibit a circadian pattern. These previous findings lead us to the overall hypotheses that endocannabinoids in the circulation convey information about the need for additional caloric intake and that sustained, high endocannabinoid concentrations contribute to overeating. The objectives of this proposal are to establish and characterize an assay system in which endocannabinoid concentrations in the circulation of awake, freely behaving rats are determined. We will examine changes in endocannabinoid concentrations across the daily cycle; and following acute food restriction and stress, as these have all been shown to impact circulating endocannabinoid concentrations in humans. We will carry out three specific aims. The first aim is to optimize the endocannabinoid measurement in rat plasma; determining the limits of detection and quantification, and robustness. The second aim is to apply the assay to measure the circadian changes in circulating endocannabinoid concentrations in relationship to other metabolic signaling molecules; and to examine the effects of a brief period of food deprivation. The third aim will examine the time course of the effects of fear-evoking odor presentation on circulating endocannabinoids. Successful completion of these studies will provide the basis for future studies, including exploration of the mechanisms by which changes in energy status affect endocannabinoids in the circulation; the tissue source of the endocannabinoids in the circulation; and, most importantly, whether the endocannabinoids entering the brain from the circulation convey information about metabolic status to brain reward circuit activity. These studies are highly translatable to humans because endocannabinoid concentrations are easily measured in human blood. Indeed, the innovation of this project lies in its "beside to bench" translation of human observations to an animal model that is amenable to mechanistic studies. The studies in this project will increase our understanding of several processes important in the regulation of circulating endocannabinoid concentrations and will set the stage for future human and animal studies of their role in eating disorders, drug addiction and mood disorders.