[Immunoregulatory role of thyroid hormone].

The immunoregulatory role of thyroid hormone was investigated in mice weighing 20-30 g. The experimental results showed that the antibody production, transformation of lymphocytes, DTH response (delayed-type hypersensitivity response) and phagocytosis of the peritoneal macrophages were all markedly enhanced when the animals were fed with a daily dose of 2 mg thyroid hormone for 14-18 days. The number of mature T cells in peripheral blood was also increased significantly by the thyroid hormone. When mice were administered with antithyroid drug (methylthiouracil), the antibody production, the transformation of lymphocytes and DTH response were inhibited. Thyroidectomy could also suppress the antibody production. The results suggest that thyroid hormone is involved in the regulation of immune function.