Departments of Neurology, Medical College of Georgia, Augusta University, USA.
Departments of Neurology, Medical College of Georgia, Augusta University, USA.
Neurochem Int. 2023 Jan;162:105457. doi: 10.1016/j.neuint.2022.105457. Epub 2022 Nov 25.
The circadian system is widely involved in the various pathological outcomes affected by time dimension changes. In the brain, the master circadian clock, also known as the "pacemaker," is present in the hypothalamus's suprachiasmatic nucleus (SCN). The SCN consists of molecular circadian clocks that operate in each neuron and other brain cells. These circadian mechanisms are controlled by the transcription and translation of specific genes such as the clock circadian regulator (Clock) and brain and muscle ARNT-Like 1 (Bmal1). Period (Per1-3) and cryptochrome (Cry1 and 2) negatively feedback and regulate the clock genes. Variations in the circadian cycle and these clock genes can affect stroke outcomes. Studies suggest that the peak stroke occurs in the morning after patients awaken from sleep, while stroke severity and poor outcomes worsen at midnight. The main risk factor associated with stroke is high blood pressure (hypertension). Blood pressure usually dips by 15-20% during sleep, but many hypertensives do not display this normal dipping pattern and are non-dippers. A sleep blood pressure is the primary determinant of stroke risk. This article discusses the possible mechanism associated with circadian rhythm and stroke outcomes.
生物钟系统广泛涉及受时间维度变化影响的各种病理结果。在大脑中，主生物钟，也称为“起搏器”，存在于下丘脑的视交叉上核（SCN）中。SCN 由在每个神经元和其他脑细胞中运行的分子生物钟组成。这些生物钟机制受特定基因的转录和翻译控制，例如时钟昼夜节律调节剂（Clock）和脑和肌肉 ARNT-Like 1（Bmal1）。Period（Per1-3）和cryptochrome（Cry1 和 2）负反馈并调节时钟基因。生物钟周期和这些时钟基因的变化会影响中风结果。研究表明，中风的高峰期发生在患者从睡眠中醒来后的早晨，而中风的严重程度和不良结果在午夜恶化。与中风相关的主要危险因素是高血压（hypertension）。血压通常在睡眠期间下降 15-20%，但许多高血压患者没有显示出这种正常的下降模式，是非杓型血压。睡眠血压是中风风险的主要决定因素。本文讨论了与昼夜节律和中风结果相关的可能机制。
