Skeletal muscle protein content and synthesis after voluntary running and subsequent unweighting

摘要: The effects of exercise training with or without subsequent unweighting on wet weight, protein content, and in vivo fractional synthesis were studied soleus plantaris muscles juvenile female Sprague-Dawley rats under the following four conditions: normal weight bearing (N), voluntary-activity wheel running (WR) for up to 4 weeks, mechanical 7 days via hindlimb suspension (HS), followed by (WR-HS). Fractional was determined 3H-phenylalanine flooding method. Increases (P < .05) content detected after just 1 week running, no increase synthesis. Two weeks required an this muscle. Significant increases these parameters first observed 2 running. Maximal occurred 3 both muscles. Reductions HS WR-HS groups compared N WR groups, respectively. However, maintained at significantly higher levels These results indicate that (1) represents a noninvasive method inducing rapid hypertrophy skeletal studied, part increasing synthesis; (2) decreases same extent whether are trained; (3) previously hypertrophied display contents unweighted untrained animals.