Thyroid peroxidase, thyroglobulin, cAMP and DNA in human thyroid.

Tissues from normal thyroid, euthyroid multinodular goiter, toxic goiter, Hashimoto's thyroiditis, thyroid adenoma, and carcinoma were examined for their content of deoxyribonucleic acid (DNA), thyroid peroxidase activity (TPA), thyroglobulin (TG), and adenosine 3',5'-cyclic monophosphate (cAMP). Compared with normal thyroids DNA was increased in the neoplastic tissues and decreased in euthyroid multinodular goiter. Quantitative changes of thyroglobulin were observed, especially in the thyroid tumors, and, in one case, immunoreactive 4S thyroglobulin-like protein was identified in the absence of 19S. TPA was grossly elevated in toxic goiter. This may be of significance in the pathogenesis of Graves' disease. TPA remained elevated even after adequate control of hyperthyroidism by preoperative PTU treatment. The cyclic AMP concentration in toxic goiter did not statistically differ from normal. This may indicate that extrathyroidal regulatory factors have a lesser role in the genesis and perpetuation of Graves' disease than otherwise believed. Cyclic AMP is known to exert a negative influence on tissue growth, and low concentrations in neoplasia have been reported. The values in the thyroid tumors studied were elevated, requiring further explanation.