Autotransplantation of thyroid tissue in rats. An experimental study.

ABSTRACT

BACKGROUND: The aim of this study is to demonstrate the functional capacity of thyroid autografts after total thyroidectomy in a rat model. MATERIALS AND METHODS: 60 rats were divided into 6 groups of 10 rats each. Thyroid gland was cut into 0.5 mm pieces and was inserted intramuscularly into the left rectus abdominis muscle at different time intervals following total thyroidectomy. The animals were observed for 30 days. Blood samples were collected weekly for TSH, FT3 and FT4 measurements. This study was conducted in strict accordance with the provisions of the law concerning test procedures on animals, as per Legislative Decree n.116/92. RESULTS: Autologous transplantations were successful in 70% of the cases. Histopathological findings showed normal thyroid architecture. It was observed that thyroid function recovered was more rapidly if the implants were performed immediately after thyroidectomy than in implants performed at a later time. These results could be due to the thyroid tissue preserving procedure used which may have led to reduce the restored thyroid function in the groups of animals where the implantation was not immediate. CONCLUSIONS: Ectopically transplanted thyroid tissue is able to survive and recover its function completely if maintained vital in an adequate preserving medium.