Osteochondral lesions in developing rats intoxicated with thallium twenty four hours after birth.

An i.p. injection of a solution of thallium acetate in deionized water at a dose of 32 mg/kg, in 24-h-old rats, produces morphological and biochemical alterations in both cartilaginous and osseous tissues. From the beginning, there are alterations in the cartilaginous cell as well as in chrondrine, osteoblasts, osseous tissue and bone marrow. Rats were sacrificed at 24, 48, and 72 h and also at 7 days. Two animals survived for 50 days. One showed total irreversible alopecia while the other one had partial alopecia with discrete recovery. Both showed a low weight and a size of 8 cm. Microscopically, degenerative changes were produced consisting of alteration and death of many cartilaginous cells, uneven metachromasia and the chondrine and decrease of the growth cartilage, scanty bone trabeculae with few osteoblasts. The bone marrow showed few myeloblasts and megakaryocytes. Progressive cellular damage throughout the 50 days of survival represents a response of the thallium ionic accumulation and recycling in cellular mitochondria of all the body's cells. This appeared in our study as irreversible and progressive osteochondral alterations with atrophy of the skin and its adnexa, hyalinization of elastic and collagenous fibers with intense interstitial edema.