Giroud Sylvain, Chery Isabelle, Bertile Fabrice, Bertrand-Michel Justine, Tascher Georg, Gauquelin-Koch Guillemette, Arnemo Jon M, Swenson Jon E, Singh Navinder J, Lefai Etienne, Evans Alina L, Simon Chantal, Blanc Stéphane
Research Institute of Wildlife Ecology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna, Vienna, Austria.
IPHC, University of Strasbourg, Strasbourg, France.
Front Physiol. 2019 Apr 12;10:389. doi: 10.3389/fphys.2019.00389. eCollection 2019.
Prior to winter, heterotherms retain polyunsaturated fatty acids ("PUFA"), resulting in enhanced energy savings during hibernation, through deeper and longer torpor bouts. Hibernating bears exhibit a less dramatic reduction (2-5°C) in body temperature, but lower their metabolism to a degree close to that of small hibernators. We determined the lipid composition, via lipidomics, in skeletal muscle and white adipose tissues ("WAT"), to assess lipid retention, and in blood plasma, to reflect lipid trafficking, of winter hibernating and summer active wild Scandinavian brown bears (). We found that the proportion of monounsaturated fatty acids in muscle of bears was significantly higher during winter. During hibernation, omega-3 PUFAs were retained in WAT and short-length fatty acids were released into the plasma. The analysis of individual lipid moieties indicated significant changes of specific fatty acids, which are in line with the observed seasonal shift in the major lipid categories and can be involved in specific regulations of metabolisms. These results strongly suggest that the shift in lipid composition is well conserved among hibernators, independent of body mass and of the animals' body temperature.
在冬季来临之前，异温动物会保留多不饱和脂肪酸（“PUFA”），通过更深、更长时间的蛰伏期，在冬眠期间提高能量储蓄。冬眠的熊体温下降幅度较小（2-5°C），但其新陈代谢降低到接近小型冬眠动物的程度。我们通过脂质组学测定了冬眠的野生斯堪的纳维亚棕熊和夏季活跃的野生斯堪的纳维亚棕熊骨骼肌和白色脂肪组织（“WAT”）中的脂质组成，以评估脂质保留情况，并测定了血浆中的脂质组成，以反映脂质运输情况。我们发现，冬季熊肌肉中的单不饱和脂肪酸比例显著更高。在冬眠期间，ω-3多不饱和脂肪酸保留在白色脂肪组织中，短链脂肪酸释放到血浆中。对单个脂质部分的分析表明特定脂肪酸有显著变化，这与主要脂质类别中观察到的季节性变化一致，并且可能参与新陈代谢的特定调节。这些结果有力地表明，脂质组成的变化在冬眠动物中得到了很好的保留，与体重和动物体温无关。
