Abstract
Male mice of dd-strain, at 4 and 8 week-ages were used at the start of the trained. The trained continued for successive during 4 to 34 week-ages and 8 to 70 week-ages. The trained group was exercised on a treadmill, and the untrained group used as control under normal laboratry condition. The skin of the right dorsum near the tail was sampled and its collagen content was examined by means of concentration of hydroxyproline. The collagen content in the skin of the trained group is lower than in that of the untrained one at each week-age, 14-18, 27-34 and 63-70 week-ages. The trained group was depressed hydroxyproline concentration of defatted skin, compared with untrained one at each weekage. The continuous exercise reduced the accumulation of collagen in the skin of mice.
