Dunlap Walter C, Fujisawa Akio, Yamamoto Yorihiro, Moylan Thomas J, Sidell Bruce D
Australian Institute of Marine Science, PMB No 3, Townsville MC, Queensland 4810, Australia.
Comp Biochem Physiol B Biochem Mol Biol. 2002 Nov;133(3):299-305. doi: 10.1016/s1096-4959(02)00150-1.
The vitamin E (VE) content of tissues from the Antarctic notothenioid fish, Chaenocephalus aceratus, Champsocephalus gunnari and Gobionotothen gibberifrons, and extracts of Antarctic krill Euphausia superba and phytoplankton collected from the Antarctic Peninsula was examined. Included in the VE composition was a newly described 'marine-derived' tocopherol (MDT), an unsaturated-isoprenoid derivative of alpha-tocopherol, that is attributed to enhancing antioxidant protection of cellular lipids at low temperature. MDT was found to co-exist with alpha-tocopherol in all Antarctic samples, ranging from 2.8 to 22.3% of the total VE composition. The highest level of VE was found in the liver of G. gibberifrons (VE=416.7 pmol/mg wet tissue) although this tissue had a low MDT composition (7.7%), whereas the greatest MDT composition was measured in the liver of C. gunnari (MDT=22.3%). In notothenioids, the pectoral adductor muscle, which has a high density of mitochondria, contained higher levels of VE than white myotomal muscle, but differences in MDT composition were small. Phytoplankton and krill also contained MDT, which supports the contention that MDT is obtained directly from the primary food chain. Our finding of MDT in Antarctic organisms is consistent with its putatively adaptive function to enhance antioxidant protection in coldwater metabolism.
对南极鲈形目鱼类裸头冰鱼、头带冰鱼和吉氏南极鱼的组织，以及从南极半岛采集的南极磷虾和浮游植物提取物中的维生素E（VE）含量进行了检测。VE成分中包括一种新描述的“海洋来源”生育酚（MDT），它是α-生育酚的不饱和异戊二烯衍生物，被认为在低温下能增强细胞脂质的抗氧化保护作用。在所有南极样本中均发现MDT与α-生育酚共存，占总VE成分的2.8%至22.3%。吉氏南极鱼肝脏中的VE含量最高（VE = 416.7 pmol/mg湿组织），不过该组织的MDT成分较低（7.7%），而头带冰鱼肝脏中的MDT成分最高（MDT = 22.3%）。在南极鲈形目鱼类中，线粒体密度高的胸鳍内收肌中的VE含量高于白色肌节肌，但MDT成分差异较小。浮游植物和磷虾中也含有MDT，这支持了MDT直接从初级食物链获取的观点。我们在南极生物中发现MDT与其在冷水代谢中增强抗氧化保护的假定适应功能一致。
