Effect of exercise on the kidney of aging mice

Quantitative light microscopic and ultrastructural kidney changes were studied in young and old mice subjected to moderate exercise. While there was little or no change in the glomeruli of the young animals, the older age-group showed progressive and statistically significant mesangial sclerosis with obliteration of capillary lumina. Electron microscopy also showed electron dense deposits in both the mesangium and subendothelium. Kidney weight in the young mice subjected to exercise was decreased when compared with the controls, while old animals showed a higher kidney weight after 6 weeks of running exercise. Our results of progressive kidney changes in old exercising animals, together with previous studies on myocardial and skeletal muscle showing parallel changes, stress the need for careful clinical studies on the possible damage of these organs in older people who engage in jogging and heavy exercise.