期刊
JOURNAL OF EXPERIMENTAL BIOLOGY
卷 214, 期 22, 页码 3732-3741出版社
COMPANY OF BIOLOGISTS LTD
DOI: 10.1242/jeb.062042
关键词
Antarctic fish; mitochondria; oxidative stress
类别
资金
- National Science Foundation [ANT 0741301, ANT-0739637]
- Directorate For Geosciences
- Division Of Polar Programs [1142720] Funding Source: National Science Foundation
- Directorate For Geosciences
- Office of Polar Programs (OPP) [0741301] Funding Source: National Science Foundation
It is unknown whether Antarctic fishes can defend themselves against oxidative stress induced by elevations in temperature. We hypothesized that Antarctic icefishes, lacking the oxygen-binding protein hemoglobin, might be more vulnerable to temperature-induced oxidative stress compared with red-blooded notothenioids because of differences in their mitochondrial properties. Mitochondria from icefishes have higher densities of phospholipids per mg of mitochondrial protein compared with red-blooded species, and these phospholipids are rich in polyunsaturated fatty acids (PUFA), which can promote the formation of reactive oxygen species (ROS). Additionally, previous studies have shown that multiple tissues in icefishes have lower levels of antioxidants compared with red-blooded species. We quantified several properties of mitochondria, including proton leak, rates of ROS production, membrane composition and susceptibility to lipid peroxidation (LPO), the activity of superoxide dismutase (SOD) and total antioxidant power (TAOP) in mitochondria isolated from hearts of icefishes and red-blooded notothenioids. Mitochondria from icefishes were more tightly coupled than those of red-blooded fishes at both 2 degrees C and 10 degrees C, which increased the production of ROS when the electron transport chain was disrupted. The activity of SOD and TAOP per mg of mitochondrial protein was equivalent between icefishes and red-blooded species, but TAOP normalized to mitochondrial phospholipid content was significantly lower in icefishes compared with red-blooded fishes. Additionally, membrane susceptibility to peroxidation was only detectable in icefishes at 1 C and not in red-blooded species. Together, our results suggest that the high density of mitochondrial phospholipids in hearts of icefishes may make them particularly vulnerable to oxidative stress as temperatures rise.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据