Gold A J, Costello L C
J Nutr. 1975 Feb;105(2):208-14. doi: 10.1093/jn/105.2.208.
Two groups of rats were provided simultaneously with a commercial stock diet for a period of 7 days. One group was fed ad libitum (control), and the other was restricted to one-fourth of the daily intake of control animals (semistarved). Body weight declined significantly in semistarved rats whereas body weight of controls increased over the 7-day period. The following were determined in vitro on mitochondria isolated from liver, kidney, and heart tissues of both groups: substrate-stimulated and DNP-uncoupled respiratory rates; specific acivities of the Krebs cycle dehydrogenases, and cytochrome c oxidase. Degradative effects of reduced food intake on mitochondrial function were observed. Uncoupled respiratory rates of liver and kidney mitochondria (using succinate as substrate) and heart mitochondria (using alpha-ketoglutarate and pyruvate) were lower. Also lower were activities of isocitrate dehydrogenase, NADP: isocitrate dehydrogenases, transhydrogenase, succinate dehydrogenase, and cytochrome c oxidase of heart mitochondria, transhdrogenase of liver mitochondria, and isocitrate dehydrogenase and transhydrogenase of kidney mitochondria. Such decreases in enzyme activities under conditions of dietary protein deficiency might have their basis in breakdown rates exceeding synthesis rates or result from partial inactivation of existing enzyme protein. Thus, there is evidence that responses to semistarvation of such parameters of mitochondrial function may differ among various tissues. In addition, liver and kidney citrate levels were lower and heart citrate level higher with semistarvation.
给两组大鼠同时提供市售普通饲料，为期7天。一组随意进食（对照组），另一组的摄入量限制为对照动物每日摄入量的四分之一（半饥饿组）。半饥饿大鼠的体重显著下降，而对照组大鼠的体重在7天内有所增加。对两组动物肝脏、肾脏和心脏组织分离出的线粒体进行了以下体外测定：底物刺激的呼吸速率和二硝基苯酚（DNP）解偶联的呼吸速率；三羧酸循环脱氢酶和细胞色素c氧化酶的比活性。观察到食物摄入量减少对线粒体功能的降解作用。肝脏和肾脏线粒体（以琥珀酸为底物）以及心脏线粒体（以α-酮戊二酸和丙酮酸为底物）的解偶联呼吸速率较低。心脏线粒体的异柠檬酸脱氢酶、NADP：异柠檬酸脱氢酶、转氢酶、琥珀酸脱氢酶和细胞色素c氧化酶，肝脏线粒体的转氢酶，以及肾脏线粒体的异柠檬酸脱氢酶和转氢酶的活性也较低。在膳食蛋白质缺乏的情况下，酶活性的这种降低可能是由于分解速率超过合成速率，或者是由于现有酶蛋白部分失活所致。因此，有证据表明，线粒体功能的这些参数对半饥饿的反应在不同组织中可能有所不同。此外，半饥饿状态下肝脏和肾脏的柠檬酸水平较低，而心脏的柠檬酸水平较高。
