Journal of Applied Physiology, Vol 44, Issue 1 50-54, Copyright © 1978 by American Physiological Society
Physical training and connective tissues in young mice: biochemistry of long bones
A. Kiiskinen and E. Heikkinen
The effect of physical training on collagen, ground substance, and nucleic
acid concentrations in long bones was studied in male mice of NMRI strain.
The mice to be trained and their controls were about 2 wk old at the
beginning of training, which took place on a 5 degrees inclined treadmill 5
days/wk for 3-22 wk. The duration of daily exercise was increased
progressively over 3 wk. The final daily exercise bouts were 50 and 80 min
for moderate programs and 180 min for the intensive program at a speed of
30 cm/s. Increased concentrations of nitrogen and hexosamines were found at
both training intensities, especially after prolonged training. No
conclusive changes in nucleic acid concentrations were observed after
training. The hexosamine-hydroxyproline ratio was higher and the
hydroxyproline-nitrogen ratio lower in the long bones of trained animals
compared to the controls. In conclusion these data suggest that prolonged
physical activity affects the organic matrix of long bones by maintaining
above average concentrations of glycosaminoglycans in matured bones.
