Preparation for oxidative stress (POS), i.e., the upregulation of endogenous antioxidants, is a widespread response of animals exposed to extreme conditions. This response has been described for more than 80 animal species belonging to eight phyla during hypometabolism or situations that limit oxygen availability. The pattern of the typical POS-response, in which a mild redox imbalance triggers antioxidant adjustments that results in increased tolerance to subsequent oxidative insults, roughly follows the curve of hormetic phenomena. A similar pattern has been reported for various animal species exposed to ultraviolet radiation (UVR) – these studies, on animals from six phyla, are discussed herein. In the light of the similarities in the redox-response of animals exposed to either oxygen restriction or UVR, we argue in this essay that UVR elicits a type of response that fits the POS theory. Exposure to UVR induces both reactive species formation and antioxidant adaptation, which is the essence of typical POS-responses. Thus, antioxidant response to UVR in animals can be categorized as a POS-type mechanism. Moreover, considering that animals are exposed to multiple stressors simultaneously in nature, this would represent an ecologically relevant process, by which one stressor (e.g., UV or ionizing radiation) may enhance the tolerance to other. We also discuss a possible role of low doses of ionizing radiation as inductor of POS-like responses in animals.

氧化应激（POS）的准备，即内源性抗氧化剂的上调，是暴露于极端条件下的动物的普遍反应。已经描述了在代谢不足或限制氧气供应的情况下，属于八门的80多种动物物种的这种反应。在典型的POS反应模式中，轻微的氧化还原失衡会触发抗氧化剂调节，从而导致其对随后的氧化损伤的耐受性增强，大致遵循仿效现象的曲线。对于暴露于紫外线辐射（UVR）的各种动物，已经报道了类似的模式-本文讨论了对来自六个门的动物的这些研究。鉴于暴露于氧气限制或UVR的动物在氧化还原反应中的相似性，我们在本文中认为，UVR引发了一种类似于POS理论的响应。暴露于UVR会诱导反应性物种形成和抗氧化剂适应，这是典型POS反应的本质。因此，动物对UVR的抗氧化剂反应可以归类为POS型机制。此外，考虑到动物在自然界中同时暴露于多种应激源，这将代表一个与生态有关的过程，通过这种过程，一种应激源（例如，紫外线或电离辐射）可以增强对另一种应激源的耐受性。我们还讨论了低剂量电离辐射作为动物中POS样反应的诱导剂的可能作用。动物对UVR的抗氧化反应可以归类为POS型机制。此外，考虑到动物在自然界中同时暴露于多种应激源，这将代表一个与生态有关的过程，通过这种过程，一种应激源（例如，紫外线或电离辐射）可以增强对另一种应激源的耐受性。我们还讨论了低剂量电离辐射作为动物中POS样反应的诱导剂的可能作用。动物对UVR的抗氧化反应可以归类为POS型机制。此外，考虑到动物在自然界中同时暴露于多种应激源，这将代表一个与生态有关的过程，通过这种过程，一种应激源（例如，紫外线或电离辐射）可以增强对另一种应激源的耐受性。我们还讨论了低剂量电离辐射作为动物中POS样反应的诱导剂的可能作用。