A low-protein diet supplemented with ketoacids plays a more protective role against oxidative stress of rat kidney tissue with 5/6 nephrectomy than a low-protein diet alone

• Published in: British journal of nutrition 2010-02, Vol.103 (4), p.608-616
• Main Authors: Gao, Xiang, Wu, Jianxiang, Dong, Zheyi, Hua, Can, Hu, Huimin, Mei, Changlin
• Format: Article
• Language: English
• Subjects: Amino acids; animal models; Animal tissues; Animals; Antioxidants - pharmacology; Antioxidants - therapeutic use; Biological and medical sciences; Body weight; Body Weight - drug effects; Chronic kidney disease; Diet; Diet, Protein-Restricted; Dietary Proteins - metabolism; Dietary restrictions; Dietary Supplements; experimental diets; Feeding. Feeding behavior; Fibrosis - prevention & control; Fundamental and applied biological sciences. Psychology; keto acids; Keto Acids - pharmacology; Keto Acids - therapeutic use; Ketoacids; Kidney - drug effects; Kidney - pathology; Kidney - physiopathology; Kidneys; Lipid Metabolism - drug effects; low protein diet; Male; Malnutrition; Nephrectomy; Nutrition research; Nutritional Supplementation; Oxidation; Oxidative stress; Oxidative Stress - drug effects; protective effect; Protein Deficiency - diet therapy; Proteins; Proteinuria - prevention & control; Random Allocation; Rats; Rats, Sprague-Dawley; Renal function; Renal Insufficiency, Chronic - diet therapy; Renal Insufficiency, Chronic - pathology; Rodents; Sclerosis - prevention & control; Serum Albumin - metabolism; tissue analysis; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114509992108

Dietary protein restriction is one major therapy in chronic kidney disease (CKD), and ketoacids have been evaluated in CKD patients during restricted-protein diets. The objective of the present study was to compare the efficacy of a low-protein diet supplemented with ketoacids (LPD+KA) and a low-protein diet alone (LPD) in halting the development of renal lesions in CKD. 5/6 Nephrectomy Sprague–Dawley rats were randomly divided into three groups, and fed with either 22 % protein (normal-protein diet; NPD), 6 % protein (LPD) or 5 % protein plus 1 % ketoacids (LPD+KA) for 24 weeks. Sham-operated rats were used as controls. Each 5/6 nephrectomy group included fifteen rats and the control group included twelve rats. Proteinuria, decreased renal function, glomerular sclerosis and tubulointerstitial fibrosis were found in the remnant kidneys of the NPD group. Protein restriction ameliorated these changes, and the effect was more obvious in the LPD+KA group after 5/6 nephrectomy. Lower body weight and serum albumin levels were found in the LPD group, indicating protein malnutrition. Lipid and protein oxidative products were significantly increased in the LPD group compared with the LPD+KA group. These findings indicate that a LPD supplemented with ketoacids is more effective than a LPD alone in protecting the function of remnant kidneys from progressive injury, which may be mediated by ketoacids ameliorating protein malnutrition and oxidative stress injury in remnant kidney tissue.