Effects of voluntary resistance exercise and high-protein snacks consisting of different proteins on bone mass and strength in rats given glucocorticoid-injections

摘要

We examined the effects of a voluntary resistance exercise together with high-protein snacks on bone mass and strength in rats given glucocorticoid-injections as a model of age-related osteopenia. Forty-eight male Wistar rats were assigned to exerciseor sedentary groups. One group was a control (C) and the other groups were glucocorticoid-injected groups. These groups were further divided into groups that received no snack (C and G), a high-protein snack containing 60% casein (GC and GEC) or containing 60% gelatin (GG and GEG). All groups were meal-fed at 8 : 30- 9 : 30 am/pm. The snack was fed at 12 : 30-13 : 00 h for 9 weeks. The exercise groups (GEC and GEG) were allowed to climb. Bone mass and strength were increased by climbing with a casein snack. The gelatin snack decreased bone weight and protein content. These results suggest that resistance exercise and high-protein snacks with good amino acid-balance may protect against osteoporosis associated with aging.