ABSTRACT
Male mice of dd-strain, at 3 weeks of age were used at the start of the exercise training. The exercise training continued successively throughout the 3 to 7 weeks of age. The trained group was divided groups ; namely, light-, middle- and heavy-trained groups, which were exercised on a treadmill. The treadmill exercise program for light-, middle- and heavy-trained groups consisted of running at speeds of 6 m/min, 10 m/min and running up a 10% grade at a speed of 12 m/min for 10 min 5 times a week, respectively. The untrained group was used as control under normal laboratory condition. The skin and Achilles tendon of the four groups were sampled and their collagen content were examined by means of concentration of hydroxyproline. The collagen content in the skin of growing mice did not recognize significant difference among the four groups. On the other hand, the collagen content in the Achilles tendon of growing mice clearly recognized significant difference between the middle-trained and untrained groups and/or between the middle-trained and light-trained groups. However, middle-exercise training reduced the accumulation of collagen in the Achilles tendon of grow. ing mice.
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.