Clarke B T
Department of Zoology, Natural History Museum, London, U.K.
Biol Rev Camb Philos Soc. 1997 Aug;72(3):365-79. doi: 10.1017/s0006323197005045.
Amphibians occupy a wide range of habitat types from arid deserts to deep freshwater lakes; they may spend most of their life underground or high in cloud forest canopy. Some are found north of the Arctic Circle and can tolerate freezing conditions, while others have evolved a range of adaptations to avoid desiccation in some of the hotter areas of the world. The skin plays key roles in the everyday survival of amphibians and their ability to exploit a wide range of habitats and ecological conditions. The normal functions of the skin are surveyed and Eisner's biorational approach to chemical prospecting--seeking clues from an animal's behaviour and its interactions with its environment to reveal the presence of chemical compounds with potential medical or veterinary applications--is applied to amphibians. The biology and natural history of amphibian skin, its glands and their secretions are briefly reviewed. Four categories of compounds are found in the granular or poison glands, these are: biogenic amines, bufodienolides (bufogenins), alkaloids and steroids, peptides and proteins. Toads, particularly members of the genus Bufo, are identified as a particularly convenient and useful source of granular gland secretions. The potential medical-pharmaceutical significance of products derived from amphibian skin secretions is discussed. The need for a humane approach to this work is noted.
两栖动物占据着从干旱沙漠到深层淡水湖等广泛的栖息地类型；它们可能一生中大部分时间生活在地下或云雾森林树冠高处。有些两栖动物分布在北极圈以北，能够耐受冰冻条件，而其他一些则进化出了一系列适应方式，以避免在世界上一些较炎热地区脱水。皮肤在两栖动物的日常生存以及它们利用广泛栖息地和生态条件的能力方面发挥着关键作用。本文对皮肤的正常功能进行了综述，并将艾斯纳的生物合理化学勘探方法——从动物行为及其与环境的相互作用中寻找线索，以揭示具有潜在医学或兽医学应用的化合物的存在——应用于两栖动物。本文简要回顾了两栖动物皮肤、其腺体及其分泌物的生物学和自然史。在颗粒腺或毒腺中发现了四类化合物，它们分别是：生物胺、蟾蜍二烯羟酸内酯（蟾蜍配基）、生物碱和类固醇、肽和蛋白质。蟾蜍，特别是蟾蜍属的成员，被确定为颗粒腺分泌物特别方便且有用的来源。本文讨论了源自两栖动物皮肤分泌物的产品在医学制药方面的潜在意义。文中指出了以人道方式开展这项工作的必要性。
