Histochemical Study of Bone in Cortisone-Treated Rats

Abstract

Subcutaneous injections of cortisone acetate to adult male rats for 3 weeks produced a loss in body weight and extreme narrowing of the epiphysial cartilage of the tibia. The diaphysis of the tibia had an ‘osteosclerotic-like’ appearance due to the fusion and the persistence of the primary trabeculae. The cortisone-treated trabeculae were characterized by a wide core of calcified cartilage lined by a thin layer of bone. These trabeculae stained a deep red with periodic acid-Schiff and very intense violet with toluidine blue. These 2 staining reactions would indicate that there was an alteration in the ground substance. This situation produced an interference in the calcification of the bone, thus inhibiting the resorption of the primary trabeculae and reorganization into their adult structure. Not only was endochondral ossification affected, but intramembranous ossification, as exemplified by the interradicular bone of the molar teeth, also showed similar changes.