The Effects of Two Different Dietary Regimens During Exercise On Outcome of Experimental Acute Kidney Injury

Abstract

Introduction: Acute kidney injury (AKI) is a syndrome characterized by rapid loss of excretory function of kidney. One of the molecules considered in the treatment of renal failure is the silent information regulator (SIRT1). In this study, the effect of two different diets during exercise on AKI was investigated. Materials and Methods: A number of rats were randomly divided into four groups; control without exercise, control with exercise, exercise + calorie restriction (CR), and exercise + time restriction (TR). Each group was divided into two subgroups of without AKI and with AKI (six rats in each group). Endurance exercise and diets were implemented before AKI. Serum urea and creatinine, urinary albumin, kidney malondialdehyde (MDA), total antioxidant capacity (TAC), transforming growth factor (TGF-β1), and SIRT1 levels, glomerular filtration rate (GFR) and relative kidney weight were measured before and 48 h after AKI induction.Results: After induction of kidney injury, serum urea and creatinine, urinary albumin, kidney MDA and TGF-β1 levels and relative kidney weight increased in rats with both previous exercise and no previous exercise (p <0.001), while GFR, and kidney TAC and SIRT1 levels decreased (p <0.001). These changes after AKI were less in the group with previous exercise than in the group that had no exercise (p <0.001). The TR diet during exercise caused a less increase in serum urea (p <0.001) and creatinine (p <0.05), and urinary albumin (p <0.01) levels after injury compared to the just exercise group. Also, both CR and TR diets during exercise caused less change in MDA (p <0.01, p <0.05, respectively) and TAC (p <0.001, p <0.05, respectively) levels compared to just exercise group. Conclusion: The results showed that exercise alone had no effect on preventing function impairment of kidney, oxidative stress, inflammation and also SIRT1 alteration following AKI in athletes, although these indexes were less among those with exercise than those without exercise. However, when the CR and TR diets were implemented during exercise, strong renoprotective effects appeared, and the protective effect of TR diet was greater.