Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Comp Biochem Physiol A Mol Integr Physiol. 2015 Aug;186:52-60. doi: 10.1016/j.cbpa.2014.08.014. Epub 2014 Aug 30.
In order for an animal to survive, the heart beat must go on in all environmental conditions, or at least restart its beat. This review is about maintaining a rhythmic heartbeat under the extreme conditions of anoxia (or very severe hypoxia) and high temperatures. It starts by considering the primitive versions of the protein channels that are responsible for initiating the heartbeat, HCN channels, divulging recent findings from the ancestral craniate, the Pacific hagfish (Eptatretus stoutii). It then explores how a heartbeat can maintain a rhythm, albeit slower, for hours without any oxygen, and sometimes without autonomic innervation. It closes with a discussion of recent work on fishes, where the cardiac rhythm can become arrhythmic when a fish experiences extreme heat.
为了使动物存活，心跳必须在所有环境条件下继续，或者至少重新开始跳动。这篇综述是关于在缺氧（或非常严重的低氧）和高温等极端条件下维持有节奏的心跳。它首先考虑了负责启动心跳的蛋白质通道的原始版本，即 HCN 通道，并披露了来自祖先有头类动物，太平洋盲鳗（Eptatretus stoutii）的最新发现。然后探讨了在没有氧气的情况下，心跳如何能够维持数小时的节奏，尽管速度较慢，有时甚至没有自主神经支配。最后讨论了最近关于鱼类的研究工作，当鱼类经历极端高温时，其心律可能会变得不规则。
