Dickerson J W, Basu T K, Parke D V
J Nutr. 1976 Feb;106(2):258-64. doi: 10.1093/jn/106.2.258.
Male Wistar weanling rats were divided into three groups and fed one of the following diets for 7, 14 and 28 days: a control diet (21% protein) fed ad libitum, a low protein diet fed ad libitum (the control diet diluted to contain 7% protein by the addition of starch) or an energy and protein restricted diet (control diet fed to provide protein intake equal to that consumed by the low protein group). The activity of glucoronyl transferase was depressed by energy restriction and cytochrome P-450 was depressed by the low protein-ad libitum energy diet compared to controls. In the animals fed the low protein diet with ad libitum energy for 14 or 28 days, the rise in the activity of biphenyl 4-hydroxylase per g liver was sufficient to compensate for the lower liver weight so that the absolute amount of enzyme activity per liver was the same as in the controls. Due to adaptive response of the enzyme to the low protein diet, the activity of biphenyl 4-hydroxylase per g liver was higher than in the controls in animals fed a protein-free diet. It is concluded that the adaptive response of biphenyl 4-hydroxylase was possibly mediated by corticosteroids and was not due to a change in the conformation of the enzyme.
雄性Wistar断乳大鼠被分为三组，并分别给予以下三种饮食之一，持续7天、14天和28天：自由采食的对照饮食（蛋白质含量21%）、自由采食的低蛋白饮食（对照饮食通过添加淀粉稀释至蛋白质含量7%）或能量和蛋白质限制饮食（给予对照饮食，使蛋白质摄入量与低蛋白组消耗的量相等）。与对照组相比，能量限制会降低葡萄糖醛酸转移酶的活性，自由采食低蛋白能量饮食会降低细胞色素P - 450的活性。在自由采食低蛋白饮食14天或28天的动物中，每克肝脏中联苯4 - 羟化酶活性的升高足以弥补肝脏重量的降低，因此每个肝脏中酶活性的绝对量与对照组相同。由于酶对低蛋白饮食的适应性反应，在喂食无蛋白饮食的动物中，每克肝脏中联苯4 - 羟化酶的活性高于对照组。得出的结论是，联苯4 - 羟化酶的适应性反应可能是由皮质类固醇介导的，而不是由于酶的构象变化。
