The aim of this report was to investigate in the albino rat the morphological effects of prolonged treatment with phenobarbital on the repair of induced diaphysary bone failure of the left radius. Forty-day-old experimental male rats (Rattus norvegicus albinus) were treated daily with subcutaneous dose of 105 mg/kg weight of phenobarbital (Gardenal, Rhodia®), for 50, 70 and 90 days of treatment. A control group was treated daily with 0.9% NaCl isotonic solution for the same periods, similar to the experimental rats. On the 30th day of treatments a 2 mm diaphysary bone failure was surgically made in the left radius of the rats of the both groups. The left radius was collected post-mortem on 20th, 40th and 60th days after the surgeries and was processed histologically for light microscope studies, with emphasis to morphometric analyses. The diaphysary bone failures of experimental rats showed a lesser volumetric range of renewed osseus tissue, when compared to the osseous tissue regeneration presented in diaphysary bone failures of control rats. The results allowed to conclude that phenobarbital prolonged treatment inhibits the osteogenesis in long bones, retarding the process of diaphysary bone failure repair in rat.
Morphology; Bones; Phenobarbital; Rats
