Voituron Yann, Verdier Bruno, Grenot Claude
Laboratoire d'Ecologie, Fonctionnement et Evolution des Systèmes Ecologiques (U. M. R. 7625), Ecole Normale Supérieure, 75230 Paris Cedex 05, France.
Am J Physiol Regul Integr Comp Physiol. 2002 Jul;283(1):R181-6. doi: 10.1152/ajpregu.00378.2001.
We investigated the respiratory metabolism of the overwintering lizard Lacerta vivipara while in either supercooled or frozen states. With a variable pressure and volume microrespirometer and a chromatograph, we show that the oxygen consumption of the supercooled animals showed a nonlinear relationship with temperature and an aerobic metabolism demand between 0.5 and -1.5 degrees C. A significant increase in the respiratory quotient (RQ) values indicated an increasing contribution by the anaerobic pathways with decreasing temperature. In the frozen state, two phases are easily detectable and are probably linked to the ice formation within the body. During the first 5-6 h, the animals showed an oxygen consumption of 3.52 +/- 0.28 microl. g(-1). h(-1) and a RQ value of 0.52 +/- 0.09. In contrast, after ice equilibrium, oxygen consumption decreased sharply (0.55 +/- 0.09 microl. g(-1). h(-1)) and the RQ values increased (2.49 +/- 0.65). The present study confirms the fact that supercooled invertebrates and vertebrates respond differently to subzero temperatures, in terms of aerobic metabolism, and it shows that aerobic metabolism persists under freezing conditions.
我们研究了胎生蜥蜴绿蜥蜴在过冷却或冷冻状态下的呼吸代谢。使用可变压力和体积的微量呼吸计以及色谱仪，我们发现过冷却动物的耗氧量与温度呈非线性关系，在0.5至 -1.5摄氏度之间存在有氧代谢需求。呼吸商（RQ）值的显著增加表明随着温度降低，无氧途径的贡献增加。在冷冻状态下，很容易检测到两个阶段，这可能与体内冰的形成有关。在最初的5 - 6小时内，动物的耗氧量为3.52±0.28微升·克⁻¹·小时⁻¹，呼吸商值为0.52±0.09。相比之下，在冰达到平衡后，耗氧量急剧下降（0.55±0.09微升·克⁻¹·小时⁻¹），呼吸商值增加（2.49±0.65）。本研究证实了这样一个事实，即过冷却的无脊椎动物和脊椎动物在有氧代谢方面对零下温度的反应不同，并且表明在冷冻条件下有氧代谢仍然存在。
