Involvement of Melatonin, Oxidative Stress, and Inflammation in the Protective Mechanism of the Carotid Artery over the Torpor–Arousal Cycle of Ground Squirrels

作者：Ziwei Hao, Yuting Han, Qi Zhao, Minghui Zhu, Xiaoxuan Liu, Yingyu Yang, Ning An, Dan He, Étienne Lefai, Kenneth B. Storey, Hui Chang, Man‐Jiang Xie · 发表于：International Journal of Molecular Sciences · 年份：2024 · DOI：10.3390/ijms252312888 · 被引用次数：3 · 研究领域：Bat Biology and Ecology Studies、Circadian rhythm and melatonin、Neuroscience of respiration and sleep

Hibernating mammals experience severe hemodynamic changes over the torpor–arousal cycle, with oxygen consumption reaching peaks during the early stage of torpor to re-enter arousal. Melatonin (MT) can improve mitochondrial function and reduce oxidative stress and inflammation. However, the regulatory mechanisms of MT action on the vascular protective function of hibernators are still unclear. Morphology, hemodynamic, mitochondrial oxidative stress, and inflammatory factors of the carotid artery were assessed in ground squirrels who were sampled during summer active (SA), late torpor (LT), and interbout arousal (IBA) conditions. Changes were assessed by methods including hematoxylin and eosin staining, color Doppler ultrasound, ELISA, Western blots, and qPCR. Changes in arterial blood and serum melatonin were also measured by blood gas analyzer and ELISA, whereas mitochondrial oxidative stress and inflammation factors of primary vascular smooth muscle cells (VSMCs) were assessed by qPCR. (1) Intima-media carotid thickness, peak systolic velocity (PSV), end diastolic blood flow velocity (EDV), maximal blood flow rate (Vmax) and pulsatility index (PI) were significantly decreased in the LT group as compared with the SA group, whereas there were no difference between the SA and IBA groups. (2) PO2, oxygen saturation, hematocrit and PCO2 in the arterial blood were significantly increased, and pH was significantly decreased in the LT group as compared with the SA and IBA groups. (3...