Thermal sensitivity of cellular energy budgets in some Antarctic fish hepatocytes
Thermal sensitivity of cellular energy budgets in some Antarctic fish hepatocytes
复制标题
一些南极鱼类肝细胞细胞能量预算的热敏感性
作者：
F. Mark;T. Hirse;H. Pörtner
研究了亚南极（Lepidonotothen larseni）和南极高海拔鱼类（Trematomus eulepidotus、pennellitrematus、lepidorhinus、bernacchii、Artedidraco orianae）的分离肝细胞中主要细胞能量消耗者引起的需氧量，以及一种zoarcid （Pachycara brachycephalum）鱼类的细胞代谢在共同定义耐热性中的作用。通过对抑制剂敏感的细胞呼吸分析，在0°C至15°C之间定量分配给蛋白质和RNA/DNA合成、离子调节和ATP合成的能量的相对比例。在所有研究物种中，蛋白质合成占总呼吸的25-37%，RNA合成占24-35%，Na+/K+-ATP酶占40-45%，线粒体ATP合成占57-65%。亚南极南极nototheniid l.l larseni的细胞蛋白质合成速率较低，但活性离子调节活性略高于其高南极同科植物，这是典型的温带物种。假设热最优反映在最小的整体细胞能量需求。亚南极L. larseni和P. brachycephalum的最小耗氧量位于3°C和6°C之间，表明在此温度以下和高于此温度时能量周转增加。相反，南极高海拔物种在变暖期间呼吸速率逐渐上升，细胞能量在0°C达到最低。南极洲nototheniid zoarcid显示cold-eurythermy的迹象,似乎生活接近热公差下限,而high-Antarctic notothenioids显示程度的能量效率高在0°C。所有细胞制剂在广泛的热范围内维持能量预算，支持了最近的概念，即整个生物体水平上的热限制是由氧气和相关的能量限制设定的。
Oxygen demand elicited by the main cellular energy consumers was examined in isolated hepatocytes of sub-Antarctic (Lepidonotothen larseni) and high-Antarctic notothenioids (Trematomus eulepidotus, Trematomus pennellii, Trematomus lepidorhinus, Trematomus bernacchii, Artedidraco orianae) and in a zoarcid (Pachycara brachycephalum) fish with respect to the role of cellular metabolism in co-defining thermal tolerance. The relative proportions of energy allocated to protein and RNA/DNA synthesis, ion regulation and ATP synthesis were quantified between 0°C and 15°C by analysis of inhibitor sensitive cellular respiration. In all the investigated species, protein synthesis constituted 25–37%, RNA synthesis 24–35%, Na+/K+-ATPase 40–45% and mitochondrial ATP synthesis 57–65% of total respiration. The sub-Antarctic nototheniid L. larseni displayed lower cellular protein synthesis rates but somewhat higher active ion regulation activities than its high-Antarctic confamilials, as is typical for more eurythermal species. Assumed thermal optima were mirrored in minimized overall cellular energy demand. In the sub-Antarctic L. larseni and P. brachycephalum, minima of oxygen consumption were located between 3°C and 6°C, indicating elevated energy turnover below and above these temperatures. In contrast, the high-Antarctic species displayed progressively rising respiration rates during warming with a cellular energetic minimum at 0°C. The sub-Antarctic nototheniid and the zoarcid showed signs of cold-eurythermy and appear to live close to their lower limit of thermal tolerance, while high-Antarctic notothenioids show high degrees of energetic efficiency at 0°C. All cellular preparations maintained energy budgets over a wide thermal range, supporting the recent concept that thermal limits are set by oxygen and associated energy limitations at the whole organism level.
DOI：
10.1152/ajpcell.00169.2002
发表时间：
2002-10
期刊：
American journal of physiology. Cell physiology
影响因子：
--
作者：
I. Tolic-Nørrelykke;J. Butler;Jianxin Chen;Ning Wang
通讯作者：
I. Tolic-Nørrelykke;J. Butler;Jianxin Chen;Ning Wang