ORGAN MASS & TISSUE METABOLIC RATES ACROSS AGE & RACE

器官质量

• 批准号: 6651317
• 负责人: DYMPNA GALLAGHER
• 金额: $ 14.86万
• 依托单位: ST. LUKE'S-ROOSEVELT INST FOR HLTH SCIS
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6651317
• 关键词: African American; adipose tissue; age difference; basal metabolism; blood chemistry; body composition; brain; caucasian American; clinical research; functional ability; gender difference; heart dimension /size; human old age (65+); human subject; kidney; liver; magnetic resonance imaging; organ; oxygen consumption; photon absorptiometry; positron emission tomography; racial /ethnic difference; striated muscles; tissues; young adult human (21-34)

Despite numerous attempts to explain the decrease in resting energy expenditure (REE) with age, and substantial variations in REE that occur between races, the mechanisms involved remain elusive. The loss of fat fee mass (FFM) cannot fully explain the decrease in RE in elderly. Since the FFM compartment consists of numerous tissues and organs, each with a different oxidative metabolic capacity, the possibility exists that changes in the proportion of these tissues with age may explain the lower REE in elderly. Moreover, REE is lower in African-American (AA) compared to Caucasian (C) metabolism at the organ/tissue level using non-invasive techniques are limited. Magnetic resonance imaging (MRI) allows for the complete reconstruction of organ and tissue volumes in vivo in combination with gated cardiac MRI. Project 4 aims are to test whether: 1) a portion of age-related changes in REE are explainable by changes in the relative fractions of high (brain, heart, liver, kidney) and low (skeletal, muscle, adipose tissue) metabolic activity tissues with respect to oxidative metabolism, 2) the cell mass fraction of skeletal muscle is reduced in elderly compared to young women and using a regional K+ counter and MRI, 3) a portion of age-related changes in REE can be explained by reductions in the metabolic activity of brain and myocardial tissues using positron emission tomography (PET) for the in vivo quantification of labeled 150 uptake, 4) there is a non-significant contribution of race to REE after appropriately measuring specific metabolically active compartments (liver, brain, kidneys, heart, skeletal muscle, adipose tissue) in AA and C adults. One hundred and sixty (20- 80 years) AA and C, healthy men and women will be measured, equally distributed to produce a 2 X 2 factorial design. A subset (n=70) of subjects will undergo additional dynamic PET studies combined with 15/O steady-state inhalation techniques to quantify brain and myocardial oxygen consumption. The proposed studies promise to anser important body composition related questions regarding the genesis of age and race differences in REE and other significant biological information.

尽管许多尝试解释了随着年龄的增长的静息能量消耗（REE）的减少，以及种族之间发生的REE的实质变化，但涉及的机制仍然难以捉摸。脂肪费质量（FFM）的损失无法完全解释老年人的RE减少。由于FFM室由许多组织和器官组成，每个组织和器官都具有不同的氧化代谢能力，因此存在随着年龄的年龄的这些组织的比例而变化的可能性可能解释了老年人的较低REE。此外，与使用非侵入性技术在器官/组织水平上的白种人（C）代谢相比，非裔美国人（AA）的REE在有限的情况下较低。磁共振成像（MRI）允许在体内完整重建器官和组织体积与门控心脏MRI结合使用。项目4的目的是测试：1）REE中与年龄相关的部分变化是否可以通过高（大脑，心脏，肝脏，肝脏，肾脏）和低（骨骼，肌肉，肌肉，脂肪组织）的相对部分的变化来解释 portion of age-related changes in REE can be explained by reductions in the metabolic activity of brain and myocardial tissues using positron emission tomography (PET) for the in vivo quantification of labeled 150 uptake, 4) there is a non-significant contribution of race to REE after appropriately measuring specific metabolically active compartments (liver, brain, kidneys, heart, skeletal muscle, adipose在AA和C成人中）。将测量一百六十（20至80年）的AA和C，健康的男人和女性，同样分布以产生2 x 2阶乘设计。受试者的子集（n = 70）将接受其他动态PET研究，并结合15/O稳态吸入技术来量化大脑和心肌氧的消耗。拟议的研究向ANSER重要的身体组成有望与REE年龄和种族差异以及其他重要生物学信息的年龄和种族差异相关的问题。