NATURAL FREEZING SURVIVAL IN ANIMALS
NATURAL FREEZING SURVIVAL IN ANIMALS
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DOI：
10.1146/annurev.ecolsys.27.1.365
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发表时间：
1996-11
期刊：
影响因子：
--
通讯作者：
K. Storey;J. Storey
中科院分区：
文献类型：
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作者：
K. Storey;J. Storey
天然的耐冻性支持许多动物的冬季生存，包括许多陆生昆虫、许多潮间带海洋无脊椎动物以及选定的陆地冬眠两栖动物和爬行动物。耐冻动物通常能够忍受 50% 或更多的体内水分转化为细胞外冰，并采取一系列适应措施来对抗冷冻的负面后果。特定的适应性控制冰形成的地点和速度，以防止冰造成的物理损害。其他适应性调节细胞体积变化：依数冷冻保护剂最大限度地减少细胞外冰形成过程中的细胞收缩；其他保护剂稳定膜结构；高密度的膜转运蛋白确保冷冻保护剂的快速分布。缺氧耐受性、代谢率降低机制和抗氧化防御也增强了细胞在冷冻过程中的存活。这些保护机制的最终结果是能够在连续冷冻数天或数周后重新激活重要功能。磁共振成像可以目视检查冰渗透耐冻青蛙和海龟体内的模式，冷冻显微镜可以说明冷冻对组织细胞和微血管结构的影响。冷冻生存的各种代谢适应似乎是从动物预先存在的生理能力进化而来的，包括抗干燥性和耐缺氧性。
Natural freeze-tolerance supports the winter survival of many animals including numerous terrestrial insects, many intertidal marine invertebrates, and selected species of terrestrially hibernating amphibians and reptiles. Freeze-tolerant animals typically endure the conversion of 50% or more of total body water into extracellular ice and employ a suite of adaptations that counter the negative consequences of freezing. Specific adaptations control the sites and rate of ice formation to prevent physical damage by ice. Other adaptations regulate cell-volume change: Colligative cryoprotectants minimize cell shrinkage during extracellular ice formation; other protectants stabilize membrane structure; and a high density of membrane transporter proteins ensure rapid cryoprotectant distribution. Cell survival during freezing is also potentiated by anoxia tolerance, mechanisms of metabolic rate depression, and antioxidant defenses. The net result of these protective mechanisms is the ability to reactivate vital functions after days or weeks of continuous freezing. Magnetic resonance imaging has allowed visual examinations of the mode of ice penetration through the body of freeze-tolerant frogs and turtles, and cryomicroscopy has illustrated the effects of freezing on the cellular and microvasculature structure of tissues. Various metabolic adaptations for freezing survival appear to have evolved out of pre-existing physiological capacities of animals, including desiccation-resistance and anoxia-tolerance.