Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada.
Compr Physiol. 2012 Jul;2(3):2151-202. doi: 10.1002/cphy.c110055.
Temperature profoundly influences physiological responses in animals, primarily due to the effects on biochemical reaction rates. Since physiological responses are often exemplified by their rate dependency (e.g., rate of blood flow, rate of metabolism, rate of heat production, and rate of ion pumping), the study of temperature adaptations has a long history in comparative and evolutionary physiology. Animals may either defend a fairly constant temperature by recruiting biochemical mechanisms of heat production and utilizing physiological responses geared toward modifying heat loss and heat gain from the environment, or utilize biochemical modifications to allow for physiological adjustments to temperature. Biochemical adaptations to temperature involve alterations in protein structure that compromise the effects of increased temperatures on improving catalytic enzyme function with the detrimental influences of higher temperature on protein stability. Temperature has acted to shape the responses of animal proteins in manners that generally preserve turnover rates at animals' normal, or optimal, body temperatures. Physiological responses to cold and warmth differ depending on whether animals maintain elevated body temperatures (endothermic) or exhibit minimal internal heat production (ectothermic). In both cases, however, these mechanisms involve regulated neural and hormonal over heat flow to the body or heat flow within the body. Examples of biochemical responses to temperature in endotherms involve metabolic uncoupling mechanisms that decrease metabolic efficiency with the outcome of producing heat, whereas ectothermic adaptations to temperature are best exemplified by the numerous mechanisms that allow for the tolerance or avoidance of ice crystal formation at temperatures below 0°C.
温度对动物的生理反应有深远影响，主要是因为它对生化反应速率的影响。由于生理反应通常表现为其速率依赖性（例如，血流速度、代谢速度、产热速度和离子泵浦速度），因此温度适应的研究在比较和进化生理学中有着悠久的历史。动物可以通过招募产热的生化机制和利用旨在调节从环境中损失和获得热量的生理反应来保持相当恒定的温度，或者利用生化修饰来允许对温度进行生理调节。温度对生物化学的适应涉及蛋白质结构的改变，这些改变削弱了温度升高对提高催化酶功能的影响，同时也对蛋白质稳定性产生了不利影响。温度作用于动物蛋白质的反应方式，通常在动物的正常或最佳体温下保持周转率。对冷和暖的生理反应因动物是否维持升高的体温（恒温动物）或表现出最小的内部产热（变温动物）而有所不同。然而，在这两种情况下，这些机制都涉及调节神经和激素以控制流向身体的热量或身体内部的热量流动。恒温动物对温度的生化反应的例子包括代谢解偶联机制，该机制降低了代谢效率，导致热量产生，而变温动物对温度的适应则最好地体现在允许在 0°C 以下温度耐受或避免冰晶形成的众多机制中。
