Iossa S, Mollica M P, Lionetti L, Barletta A, Liverini G
Department of General and Environmental Physiology, University of Naples "FEDERICO II", Italy.
Br J Nutr. 1997 Jan;77(1):99-105. doi: 10.1017/s0007114500002919.
In the present study energy balance and liver respiratory activity were studied in rats fed on either a control diet or an energy-dense diet. Liver respiration was assessed both without added substrates and after the addition of hexanoate, glycerol, or sorbitol. The effect of ouabain on hexanoate-supported respiration was also determined. Metabolizable energy intake and energy expenditure increased in rats fed on an energy dense diet, but body-weight gain, as well as lipid and protein content, remained unchanged. When net energy expenditure, obtained excluding the total cost of storage, was expressed as a percentage of metabolizable energy, significant differences were found between the two groups of rats. This finding supports the presence of regulatory mechanisms in rats fed on an energy-dense diet, which are useful to counteract development of obesity. In addition, a significant increase in liver respiratory activity was found in rats fed on an energy-dense diet, both in the basal state and in that stimulated by added substrates. Na/K-pump-dependent O2 consumption also increased in rats fed on an energy-dense diet. The results indicate that a greater production of metabolic heat by the liver can contribute to the increased energy expenditure found in rats fed on an energy-dense diet.
在本研究中，对喂食对照饮食或能量密集型饮食的大鼠的能量平衡和肝脏呼吸活性进行了研究。在不添加底物以及添加己酸盐、甘油或山梨醇后评估肝脏呼吸。还测定了哇巴因对己酸盐支持的呼吸的影响。喂食能量密集型饮食的大鼠的可代谢能量摄入量和能量消耗增加，但体重增加以及脂质和蛋白质含量保持不变。当将排除储存总成本后获得的净能量消耗表示为可代谢能量的百分比时，两组大鼠之间存在显著差异。这一发现支持了喂食能量密集型饮食的大鼠中存在调节机制，这些机制有助于抵消肥胖的发展。此外，在喂食能量密集型饮食的大鼠中，无论是基础状态还是添加底物刺激后的状态，肝脏呼吸活性均显著增加。喂食能量密集型饮食的大鼠中依赖钠/钾泵的氧气消耗也增加。结果表明，肝脏产生更多的代谢热可导致喂食能量密集型饮食的大鼠能量消耗增加。
