[Quantitative evaluation of the degree of bone tissue deposition in sponge-like skeletal segments experimentally subjected to mechanical stress].

A 12-month old dog was sacrificed 4 months after fixation of the left anterior limb, in a cutaneous pouch, to the thoracic wall, and division of the ipsilateral brachial plexus; 27 and 7 days before sacrifice, Alizarin red (20 mg/Kg) was injected intravenously. Rarefaction of spongy bone and increase in the rate of osteogenic activity were recorded from the sections of the distal end of the unloaded left radius compared to the corresponding part of the control bone. The events mentioned appeared more marked in the "tubular" than in the "lamellar" spongiosa. These findings seem to offer new evidence supporting the suggestion that in adult life bone tissue reconstruction rate is relatively higher in the areas of spongy bone comparatively less involved in the mechanical resistance.