Stables Catherine L, Auerbach David S, Whitesall Steven E, D'Alecy Louis G, Feldman Eva L
Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA.
Auton Neurosci. 2016 Jan;194:17-25. doi: 10.1016/j.autneu.2015.12.006. Epub 2015 Dec 17.
Cardiac autonomic dysfunction is a serious complication of diabetes. One consequence is disruption of the normal beat-to-beat regulation of heart rate (HR), i.e. HR variability (HRV). However, our understanding of the disease process has been limited by inconsistent HR/HRV data from previous animal studies. We hypothesized that differences in the method of measurement, time of day, and level of stress account for the differing results across studies. Thus, our aim was to systematically assess HR and HRV in two common diabetic mouse models.
ECG radiotelemetry devices were implanted into db/db (type-2 diabetic), STZ-treated db/+ (type-1 diabetic), and control db/+ mice (n=4 per group). HR and HRV were analyzed over 24 h and during treadmill testing.
24 h analysis revealed that db/db mice had an altered pattern of circadian HR changes, and STZ-treated mice had reduced HR throughout. HRV measures linked to sympathetic control were reduced in db/db mice in the early morning and early afternoon, and partially reduced in STZ-treated mice. HR response to treadmill testing was blunted in both models.
It is important to consider both time of day and level of stress when assessing HR and HRV in diabetic mice. db/db mice may have altered circadian rhythm of sympathetic control of HR, whereas STZ-treated mice have a relative reduction. This study provides baseline data and a framework for HR analysis that may guide future investigations.
心脏自主神经功能障碍是糖尿病的一种严重并发症。其后果之一是破坏心率（HR）的正常逐搏调节，即心率变异性（HRV）。然而，我们对该疾病过程的理解一直受到以往动物研究中HR/HRV数据不一致的限制。我们假设测量方法、一天中的时间以及应激水平的差异导致了各研究结果的不同。因此，我们的目的是系统评估两种常见糖尿病小鼠模型中的HR和HRV。
将心电图无线电遥测装置植入db/db（2型糖尿病）、经链脲佐菌素（STZ）处理的db/+（1型糖尿病）和对照db/+小鼠（每组n = 4）。在24小时内以及跑步机测试期间分析HR和HRV。
24小时分析显示，db/db小鼠的昼夜HR变化模式改变，经STZ处理的小鼠HR整体降低。与交感神经控制相关的HRV指标在清晨和下午早些时候的db/db小鼠中降低，在经STZ处理的小鼠中部分降低。两种模型中对跑步机测试的HR反应均减弱。
在评估糖尿病小鼠的HR和HRV时，考虑一天中的时间和应激水平很重要。db/db小鼠可能改变了HR交感神经控制的昼夜节律，而经STZ处理的小鼠则相对降低。本研究提供了基线数据和HR分析框架，可能指导未来的研究。
