[Tetracycline in the evaluation of bone turnover]

A new and easy technique for the fluorimetric evaluation of rolitetracycline calcium complex was studied. The study was carried out in 3 different groups of rats; an increase in power of fluorescence in the rats on a low calcium diet (LC) and on a low calcium diet plus vitamin D (LC + D) versus the group of rats on a normal calcium diet (NC) was found. Moreover, the amount of spongy bone showed a significant decrease in bone mass in the first two groups (LC and LC + D) versus control. These data indicated that the bone tie of tetracycline was only related to the high turnover of bone and there was no relationship with bone mass. This new technique, in comparison with the others, (double marking and evaluation of space between the two fluorescent bands) enables to evaluate the kind and the evolution of bone rarefaction by biopsy.