Combination of exercise and enalapril enhances renoprotective and peripheral effects in rats with renal ablation

Background: It is suggested that appropriate chronic exercise (EX) may produce improvements of the physical strength in patients with chronic renal failure (CRF). Because acute exercise causes proteinuria and decreases the renal blood flow and glomerular filtration rate, it is necessary to consider the influence of EX on renal function. Therefore, we assessed the renal and peripheral effects of moderate to intense EX as well as the effects of the combination of EX and enalapril (ENA) in a rat model of CRF. Methods: Male 5/6-nephrectomized Wistar-Kyoto rats were divided into six groups according to the following treatment: 1) no exercise (C); 2) ENA (2 mg/kg/day, subcutaneously); 3) moderate exercise with treadmill running (20 m/min for 60 min/day, 5 days/week) (EXm); 4) intense exercise with treadmill running (28 m/min for 60 min/day, 5 days/week) (EXi); 5) EXm+ENA; and 6) sham operation (S). The rats were then treated for 12 weeks. Results: Both EX and ENA blocked the development of hypertension, blunted increases in proteinuria, reduced serum creatinine and blood urea nitrogen, and improved the index of glomerular sclerosis (IGS) and the relative interstitial volume of the renal cortex (RIV). Moreover, IGS and RIV in the EXm+ENA group were the lowest among all other nephrectomized groups. Furthermore, EXm+ENA enhanced capillarization as well as the proportion of type-I fiber in the soleus muscle. Conclusions: These results suggest that EX and ENA have renoprotective effects. The findings also suggest that EXm+ENA provided greater renoprotective effects than those of ENA alone, and that EXm+ENA had some additional peripheral effects without any complications in this rat model.