2000 Volume 38 Issue 4 Pages 803-820
In order to evaluate the effect of physical training and calcium intake on bone formation, we used thirty Wistar male rats, six weeks of age weighing around 160 g, for the present study. The animals were divided randomly into six groups as follows: group A (standard diet and no exercise), group B (standard diet, one hour training per day), group C (standard diet, two hours training per day), group D (calcium deficient diet, no special training), group E (calcium deficient diet, one hour training per day), group F (calcium deficient diet, two hours training per day). The results obtained were as follows:
1. Body weight
There were significance differences were found when group E was compared with group A, group B, group C and group D.
2. Histopathological findings
Compared to group A, the number of hypertrophy chondrocytes decreased in group B, while the calcified matrix increased and more chondroclast were seen. The endochondral ossification was more active. In the primary spongy bone, the number of osteoblasts surrounding the calcified matrix increased and the number of osteocytes increased too.
The cartilage width of group C was winder than that of group B, and there were more chondrocytes. The chondrocytes in the zone of proliferation and hypertrophy arranged regularly and closely. The intrusiveness of calcified matrix was easily seen and the endochodral ossification was active in group C.
Comparing group D to the control group, we found some changes as follows. The width of the reserve cartilage zone increased, chondrocytes in proliferation zone deformed and decreased, the calcified matrix and chondroclast decreased, accompanied by a decrease in calcified matrix absorption and delay in the trabeculae formation while the newly formed trabecular was thin.
In contrast to group D, group E showed that the number of reserve zones decreased, the chondrocytes in proliferation arranged closely, the intrusiveness of calcified matrix increased, and the trabecular formation decreased as well.
In contrast to group E, group F showed that the number of chondrocyte and chondroclased decreased, and trabecular formation was hardly seen.
These results suggested that the physical training could improve bone formation but this effect could not be seen when rats suffered from a calcium deficiency.
