Gil P, Alonso-Bedate M, Barja de Quiroga G
Departamento de Fisiología Animal, Facultad de Biología, Universidad Complutense, Madrid, Spain.
Free Radic Biol Med. 1987;3(2):137-46. doi: 10.1016/s0891-5849(87)80009-6.
Studies about the proposed antioxidant physiological role of the catalase (CAT) enzyme in relation to different environmental oxygen tensions are reported for the first time in amphibian larvae of Discoglossus pictus and Rana ridibunda perezi during their development. The CAT levels of whole tadpoles increased constantly in both species during the larval period, reaching a maximum during the metamorphic climax. All through development, CAT activity levels were always greater in D. pictus than in R. ridibunda perezi. This correlates well with the already reported higher SOD activity and hyperoxia resistance of the D. pictus species when compared to R. ridibunda perezi. Long-term acclimation to different levels of hyperoxia (40, 60, and 100% O2) showed dose-related increases in the CAT activity of D. pictus tadpoles. These increases did not take place when the animals were subjected to acute hyperoxia (24 h). The increase in CAT activity observed after 15 days of acclimation to acute hyperoxia (710 mm Hg: 100% O2) was reversed after 15 additional days of postacclimation to normal air (149 mm Hg O2). When recently metamorphosed frogs were acclimated to acute hyperoxia, significant increases in CAT activity were observed after 15 days, but not after 7 days. The results are interpreted as supporting a protective role for the CAT enzyme in amphibian larvae and froglets against oxygen toxicity.
首次报道了关于过氧化氢酶（CAT）在不同环境氧张力下的拟抗氧化生理作用的研究，该研究以饰纹姬蛙和泽陆蛙的两栖类幼体在发育过程中为对象。在幼体期，两种蛙的整个蝌蚪体内的CAT水平均持续升高，在变态高峰期达到最高值。在整个发育过程中，饰纹姬蛙的CAT活性水平始终高于泽陆蛙。这与之前报道的饰纹姬蛙相比泽陆蛙具有更高的超氧化物歧化酶（SOD）活性和抗高氧能力密切相关。长期适应不同水平的高氧环境（40%、60%和100% O₂）显示，饰纹姬蛙蝌蚪的CAT活性呈剂量相关增加。当动物遭受急性高氧环境（24小时）时，这种增加并未发生。在适应急性高氧环境（710毫米汞柱：100% O₂）15天后观察到的CAT活性增加，在随后再适应正常空气（149毫米汞柱O₂）15天后逆转。当刚变态的青蛙适应急性高氧环境时，15天后观察到CAT活性显著增加，但7天后未观察到。结果被解释为支持CAT酶在两栖类幼体和幼蛙中对氧毒性具有保护作用。
