Kashiwagi Aki, Hosokawa Sachiko, Maeyama Yoshihiro, Ueki Ryusuke, Kaneki Masao, Martyn J A Jeevendra, Yasuhara Shingo
From the Department of Anesthesiology, Critical Care and Pain Medicine, Massachusetts General Hospital, Shriners Hospital for Children and Harvard Medical School, Boston, Massachusetts (A.K., S.H., R.U., M.K., J.A.J.M., S.Y.); and Department of Surgery, Hyogo College of Medicine, Kobe, Japan (Y.M.). Current affiliation: Stem Cell Bank, Center for Stem Cell Biology and Regenerative Medicine, Institute of Medical Science, University of Tokyo, Tokyo, Japan (Y.M.).
Anesthesiology. 2015 May;122(5):1075-83. doi: 10.1097/ALN.0000000000000561.
It has been known that skeletal muscles show atrophic changes after prolonged sedation or general anesthesia. Whether these effects are due to anesthesia itself or disuse during anesthesia has not been fully clarified. Autophagy dysregulation has been implicated in muscle-wasting conditions. This study tested the hypothesis that the magnitude of skeletal muscle autophagy is affected by both anesthesia and immobility.
The extent of autophagy was analyzed chronologically during general anesthesia. In vivo microscopy was performed using green fluorescent protein-tagged LC3 for the detection of autophagy using sternomastoid muscles of live mice during pentobarbital anesthesia (n = 6 and 7). Western blotting and histological analyses were also conducted on tibialis anterior muscles (n = 3 to 5). To distinguish the effect of anesthesia from that due to disuse, autophagy was compared between animals anesthetized with pentobarbital and those immobilized by short-term denervation without continuation of anesthesia. Conversely, tibialis anterior and sternomastoid muscles were electrically stimulated during anesthesia.
Western blots and microscopy showed time-dependent autophagy up-regulation during pentobarbital anesthesia, peaking at 3 h (728.6 ± 93.5% of basal level, mean ± SE). Disuse by denervation without sustaining anesthesia did not lead to equivalent autophagy, suggesting that anesthesia is essential to cause autophagy. In contrast, contractile stimulation of the tibialis anterior and sternomastoid muscles significantly reduced the autophagy up-regulation during anesthesia (85% at 300 min). Ketamine, ketamine plus xylazine, isoflurane, and propofol also up-regulated autophagy.
Short-term disuse without anesthesia does not lead to autophagy, but anesthesia with disuse leads to marked up-regulation of autophagy.
已知长时间镇静或全身麻醉后骨骼肌会出现萎缩性变化。这些影响是由于麻醉本身还是麻醉期间的废用尚未完全阐明。自噬失调与肌肉萎缩状况有关。本研究检验了骨骼肌自噬程度受麻醉和不动状态两者影响的假设。
在全身麻醉期间按时间顺序分析自噬程度。使用绿色荧光蛋白标记的LC3进行体内显微镜检查，以检测戊巴比妥麻醉期间活小鼠胸锁乳突肌的自噬情况（n = 6和7）。还对胫前肌进行了蛋白质印迹和组织学分析（n = 3至5）。为了区分麻醉与废用的影响，比较了戊巴比妥麻醉的动物和短期去神经支配而未继续麻醉的固定动物的自噬情况。相反，在麻醉期间对胫前肌和胸锁乳突肌进行电刺激。
蛋白质印迹和显微镜检查显示戊巴比妥麻醉期间自噬呈时间依赖性上调，在3小时达到峰值（基础水平的728.6±93.5%，平均值±标准误）。无麻醉维持的去神经支配导致的废用未引起同等程度的自噬，表明麻醉对于引起自噬至关重要。相比之下，对胫前肌和胸锁乳突肌的收缩刺激显著降低了麻醉期间的自噬上调（300分钟时降低85%）。氯胺酮、氯胺酮加赛拉嗪、异氟烷和丙泊酚也上调了自噬。
无麻醉的短期废用不会导致自噬，但麻醉伴废用会导致自噬显著上调。
