H2S induced hypometabolism in mice is missing in sedated sheep
H2S induced hypometabolism in mice is missing in sedated sheep
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DOI：
10.1016/j.resp.2007.09.001
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发表时间：
2008-01-01
影响因子：
2.3
通讯作者：
Bihain, Bernard
中科院分区：
文献类型：
--
作者：
Haouzi, Philippe;Notet, Veronique;Bihain, Bernard
在小鼠中进行的研究表明，H2S吸入会显著降低代谢率，基于此，H2S被提议作为保护人类重要器官免受创伤或缺血发作的一种手段。事实上，长期以来，缺氧也被证明会引起代谢减退。然而，这种效应仅在具有高V-O2 kg（-1）的小型动物中观察到，而在大型哺乳动物中没有观察到。因此，推断H2S对大型哺乳动物的低代谢作用是值得怀疑的，可能是潜在的危险。我们测量了在23-24摄氏度的环境温度下暴露于H2S（60 ppm）的清醒小鼠（24 g）的代谢。H2S导致气体交换率快速大幅（50%）下降，这与体温变化无关。代谢反应发生在不到3分钟内。相比之下，在22摄氏度的环境温度下进行类似挑战期间，用氯胺酮镇静且体重74 kg的绵羊未表现出任何代谢率降低。虽然H2S诱导的小鼠代谢减退的一部分与活动减少有关，但我们推测绵羊和小鼠之间的差异可能取决于基础代谢率与体重之间关系的性质和特征，从而取决于根据体重控制静息代谢率的不同机制。因此，鉴于在大型镇静哺乳动物中缺乏低代谢作用和H2S已确立的毒性，应重新考虑将H2S给药作为保护重要器官的一种方法的拟定用途。(c)2007 Elsevier B. V.保留所有权利。
On the basis of studies performed in mice that showed H2S inhalation decreasing dramatically the metabolic rate, H2S was proposed as a means of protecting vital organs from traumatic or ischemic episodes in humans. Hypoxia has in fact also long been shown to induce hypometabolism. However, this effect is observed solely in small-sized animals with high V-O2 kg(-1), and not in large mammals. Thus, extrapolating the hypometabolic effect of H2S to large mammals is questionable and could be potentially dangerous. We measured metabolism in conscious mice (24 g) exposed to H2S (60 ppm) at an ambient temperature of 23-24 degrees C. H2S caused a rapid and large (50%) drop in gas exchange rate, which occurred independently of the change in body temperature. The metabolic response occurred within less than 3 min. In contrast, sheep, sedated with ketamine and weighing 74 kg did not exhibit any decrease in metabolic rate during a similar challenge at an ambient temperature of 22 degrees C. While a part of H2S induced hypometabolism in the mice is related to the reduction in activity, we speculate that the difference between sheep and mice may rely on the nature and the characteristics of the relationship between basal metabolic rate and body weight thus on the different mechanisms controlling resting metabolic rate according to body mass. Therefore, the proposed use of H2S administration as a way of protecting vital organs should be reconsidered in view of the lack of hypometabolic effect in a large sedated mammal and of H2S established toxicity. (c) 2007 Elsevier B.V. All rights reserved.