Exercise training ameliorates progressive renal disease in rats with subtotal nephrectomy

Abstract

To determine the effect of chronic exercise training on renal function in animals with moderate renal insufficiency, rats with 75% renal ablation were either exercise trained by swimming for two months or remained sedentary. Glomerular filtration rate was significantly higher in trained (1.89 +/- 0.07 ml/min) than in sedentary rats (1.52 +/- 0.11 ml/min). No change was observed in renal blood flow or the degree of hypertension. Proteinuria was reduced in trained (13.6 +/- 4.9 mg/24 hr) compared to sedentary animals (33.5 +/- 9.2 mg/24 hr). The degree of glomerulosclerosis was much less prominent in trained animals. Plasma, low-density lipoprotein cholesterol-levels and total triglycerides were reduced in trained compared to sedentary rats. This study suggests that chronic exercise training ameliorates the progression of renal disease and improves plasma lipids in rats with moderate renal insufficiency. The mechanism for this improvement in renal function appears to be independent of the influence of systemic blood pressure.

Effect of Exercise Training on Glomerular Filtration Rate of Mice with Various Degrees of Renal Mass Reduction

“…This result would suggest that in these animals, either the normal physiological events triggered by physi cal activity were not set into motion or that the remnant kidney tissue was devoid of any reserve capacity with respect to GFR. Our results are apparently in contrast to those of Heifetz et al [5] who found a significant increase in inulin clearance in 3/4-nephrectomized rats following physical exertion compared to an unexerted control group. However, their experimental protocol involved swimming in water at 37 °C.…”

“…It has been shown in healthy humans [1-3] and ani mals [4,5] that acute physical activity is associated with a decrease in both glomerular filtration rate (GFR) and renal plasma flow. GFR declines to a lesser extent than renal plasma flow, thus, filtration fraction rises [2, 3, 6], During acute physical effort, a rise is recorded in serum levels of renin, angiotensin II, aldosterone, antidiuretic hormone [7] and natriuretic peptide [8], all potentially capable of modifying these renal parameters.…”

Exercise Training and the Progression of Chronic Renal Failure

“…Exercise in the rats was much heavier than in the patients and included 2 h of daily swimming [1,2]. This was associated with a reduc tion in proteinuria and a fall in LDL cholesterol and tri glyceride in plasma, in support of the hypothesis of an effect of plasma lipids on the progression of renal disease [14][15][16], Blood pressure apparently was not influenced by exercise training in the rats.…”

“…Two experimental studies in rats have demonstrated that a program of regular physical exercise mitigates the progression of chronic renal failure (CRF) [1,2], Con trolled physical exercise programs can improve the well being and exercise capacity of patients with CRF, both before [3] and after the start of dialysis [4], The effect of exercise on the course of progression of CRF in man has not been studied. It has traditionally been inferred that physical exercise might be harmful to kidneys with an impaired function, as heavy bouts of exercise regularly causes a transient fall in renal blood flow [5], transient proteinuria [6] and in the urinary sediment a picture of 'athlete pscudonephritis' with erythrocytes and granular casts [7], These transient effects have not been reported to cause any impairment of renal function.…”

Exercise Training and the Progression of Chronic Renal Failure

“…We suggest that our results in the latter group are more indicative than those of the two studies mentioned [3, 4] since in these studies the imposed physical activity consisted of swimming and involved water immersion and exposure to a high environmental temperature (37°C). Each of those two elements triggered a chain of physiological events, such as a rise in central blood volume and activation of various relevant hormonal systems, which could alter the pure effect of physical activity on GFR.…”