Abstract
This study was carried out to investigate changes in the mandibular condyle, femoral head and vertebral trabeculae in rats with experimental osteoporosis induced by triethylene thio-phosphoramide (TEPA).
Wistar rats were divided into 2 groups: the normal group was given distilled water, and the TEPA group was given 10mg/kg of TEPA by hypodermic injection. Histopathological observation and measurement of quantitative percentages of trabecular areas, determined by binary images of the mandibular condyle, femoral head and fourth lumbar vertebra, were made 3 days, 5 days, 7 days, 10 days, and 14 days after the injection.
Histopathological observation showed that the cartilage layers had thinned, the cells of cartilage had decreased and dwarfed, and the matrix of cartilage and bone had decreased, especially at 5 days and 7 days in the TEPA group.
By trabecula area percentages, a decrease in area was found in the TEPA group, and the largest decrease was at 5 days after the injection.
An analysis of variance was made of the trabecular area percentages between the normal group and the TEPA group at the mandibular condyle, femoral head and fourth lumbar vertebra. The contribution ratios of the factor of TEPA injection were calculated with the following results: mandibular condyle, 30.63%; femoral head, 64.14%; fourth lumbar vertebra, 10.30%.
Therefore, the greatest decrease in bone area percentages in experimental osteoporosis induced by TEPA in rats was at the femoral head, followed by the mandibular condyle; the decrease in the fourth lumbar vertebra was found to be very slight.
