Schoolwerth A C, Sandler R S, Hoffman P M, Klahr S
Kidney Int. 1975 Jun;7(6):397-404. doi: 10.1038/ki.1975.57.
Urinary ammonium excretion, in vitro ammoniagenesis and the activities of renal cortical phosphate-dependent glutaminase (PDG) and glutamic dehydrogenase (GLDH) were measured in rats with a reduced renal mass. Following contralateral nephrectomy, ammonium excretion per nephron, ammonia production and the activities of PDG and GLDH were all increased significantly in remnant kidneys of rats fed high protein diets. In rats fed low protein diets, although PDG activity increased, GLDH activity and ammonia production and excretion did not increase in remnant kidneys following contralateral nephrectomy. Ammonia production and excretion were greater in rats fed high than low protein diets, a difference that was corrected by the addition of mineral acid to the diets of low protein-fed rats. Acid supplementation to the low protein group did not result in enhanced ammonia production or GLDH activity following a reduction in renal mass. The data indicate that the increased rate of ammoniagenesis which occurs following nephron reduction is markedly influenced by dietary protein content. A lack of enhanced GLDH activity may underlie the lack of increased ammonia production of low protein-fed rats following nephron reduction.
在肾质量减少的大鼠中，测定了尿铵排泄、体外氨生成以及肾皮质磷酸依赖性谷氨酰胺酶（PDG）和谷氨酸脱氢酶（GLDH）的活性。对大鼠进行对侧肾切除术后，在喂食高蛋白饮食的大鼠残余肾中，每个肾单位的铵排泄、氨生成以及PDG和GLDH的活性均显著增加。在喂食低蛋白饮食的大鼠中，尽管对侧肾切除术后残余肾中的PDG活性增加，但GLDH活性、氨生成及排泄并未增加。喂食高蛋白饮食的大鼠的氨生成及排泄量高于喂食低蛋白饮食的大鼠，通过向喂食低蛋白饮食的大鼠饮食中添加无机酸可纠正这一差异。在肾质量减少后，向低蛋白组补充酸并未导致氨生成增加或GLDH活性增强。数据表明，肾单位减少后氨生成速率的增加明显受饮食蛋白质含量的影响。低蛋白饮食喂养的大鼠在肾单位减少后氨生成未增加，可能是由于GLDH活性未增强。
