Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA.
Longevity Institute, Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA.
Methods Mol Biol. 2020;2144:125-129. doi: 10.1007/978-1-0716-0592-9_11.
Basic preclinical research on the pathophysiology of aging-related and/or metabolic diseases, including type 2 diabetes, largely relies on animal models. Mice, the most commonly used species to study the biological processes that regulate aging and its associated functional decline, have helped researchers to identify pathways, mechanisms, and genes that regulate aging-related diseases and aging itself and thus are intervention targets. Changes in energy metabolism are a central component of the biological processes that undergo significant alterations with age. For example, the prevalence of type 2 diabetes and impaired glucose tolerance increases with aging. Not surprisingly, the characterization of these changes for metabolic phenotyping is commonly found in laboratories around the world. Glucose tolerance tests (GTT) and insulin tolerance tests (ITT) do not require surgery, are relatively easy to perform, and, most importantly, are minimally invasive and are thus the preferred method to evaluate glucose homeostasis in the aging animal. Both assays measure blood glucose following the bolus injection of either glucose (for GTT) or insulin (for ITT). Although they are standard procedures, the interpretation of both assays is strongly influenced by laboratory practices and variable experimental conditions. Here, we aim to provide simple guidelines that can be useful to standardize GTT and ITT in the aging mouse.
基础的衰老相关疾病和/或代谢性疾病（包括 2 型糖尿病）的病理生理学的临床前研究主要依赖于动物模型。老鼠是最常用于研究调节衰老及其相关功能衰退的生物学过程的物种，它帮助研究人员鉴定了调控衰老相关疾病和衰老本身的途径、机制和基因，从而成为干预靶点。能量代谢的变化是随着年龄的增长而发生显著改变的生物学过程的一个核心组成部分。例如，2 型糖尿病和葡萄糖耐量受损的患病率随着年龄的增长而增加。毫不奇怪，这些代谢表型特征的描述在世界各地的实验室中都很常见。葡萄糖耐量试验（GTT）和胰岛素耐量试验（ITT）不需要手术，相对容易进行，最重要的是，它们微创且因此是评估衰老动物葡萄糖稳态的首选方法。这两种检测方法都是在给动物注射葡萄糖（用于 GTT）或胰岛素（用于 ITT）后测量血糖。尽管它们是标准程序，但这两种检测方法的解释都受到实验室操作和可变实验条件的强烈影响。在这里，我们旨在提供一些简单的准则，以帮助标准化衰老小鼠中的 GTT 和 ITT。
