PVG rats, resistant to experimental allergic thyroiditis, develop high serum levels of thyroglobulin after sensitization.

Following challenge with rat thyroglobulin and adjuvants, DA rats invariably develop the histological features of severe experimental allergic thyroiditis while the thyroid glands of PVG rats remain histologically normal. It has been reported previously that some PVG rats develop high titers of anti-thyroglobulin antibody when challenged despite apparent resistance to thyroiditis. In the present experiment, PVG rats consistently developed high serum levels of both antibody and thyroglobulin. Although release of thyroglobulin from the thyroid is usually considered an indication of damage to the gland, the thyroid remained completely normal in all challenged PVG rats.