RESUMO
Objective:To investigate the effect of a low calcium diet on the distal and proximal tibial metaphysis in male rats using bone histomorphometrical techniques. Methods:Forty 3-month-old male Sprague-Dawley(SD) rats, with a mean weight of 280?22g, were randomized into five groups. Group one and group two were fed a normal diet (Ca 1.0%) and a very low calcium diet (VLCD ,Ca 0.1%) respectively for one month,and the rest three groups were fed a normal diet (Ca 1.0%), a very low calcium diet (VLCD, Ca 0.1%) and a low calcium diet (LCD , Ca 0.3%) respectively for three months. All animals received double bone fluorochrome labeling prior to sacrifice. At the end of experiment, the left tibiae were harvested for bone histomorphometrical evaluations. Results:After one month, compared to control group, distal tibial metaphysis(DTM) of VLCD did not change significantly but proximal tibial metaphysis(PTM) was decreased significantly whose percent trabecular area (%Tb.Ar) was decreased to 38% (P