Human Thyroid Peroxidase Activity in Benign and Malign Thyroid Disorders

Abstract

Peroxidase activity in various human benign and malignant pathological conditions has been investigated. The activity was measured in vitro by oxidation of iodide and by iodination of bovine serum albumin (BSA). The deficiency of hormone synthesis observed in various diffuse benign thyroid disorders was certainly not due to a lack of peroxidase activity. In hyperthyroid patients treated with carbimazole and in a euthyroid state at surgery, iodide-peroxidase activity (24 patients) and DNA content (12 patients), both expressed per g of wet weight, were enhanced (288% and 122% increases over control, respectively) and the cellular enzyme activity was almost double than that of normal tissue. An increase in peroxidase activity when measured by iodination of BSA (11 patients) was also observed (350% increase over control). It is suggested that high cellular peroxidase activity might be due not to the treatment but to the disease. In euthyroid patients with diffuse sporadic goiter, the peroxidase activity measu...