To clarify whether the changes of free radicals and its scavengers are induced by
thyroid disorders, we measured levels of free radical scavengers and checked O2 radical generating systems in the human thyroid gland.
Thyroid specimens from patients with Graves' disease, follicular adenoma, and papillary
and follicular carcinomas contained significantly higher concentrations of xanthine
oxidase (XOD) and gluthathione peroxidase (GSH-PX), compared to those in the normal
thyroid tissue. Catalase concentration was significantly lower in thyroid specimens
from patients with Graves' disease and significantly lower in thyroid specimens from
patients with follicular adenoma, compared to those in the normal thyroid tissue.
Cu/Zn superoxide dismutase (Cu/Zn SOD) concentration was significantly lower in the
specimens from follicular adenoma and papillary carcinoma and Mn SOD concentration
was significantly higher in the specimens from papillary carcinoma than those in the
normal thyroid tissue. The lipid peroxide concentration, expressed as malondialdehyde
(MDA) concentration, was significantly higher in the specimens from papillary carcinoma
than those in the normal thyroid tissue.
These findings suggest that the levels of free radicals are increased and are scavenged
and catalyzed in the thyroid of Graves' disease, whereas free radicals and lipid peroxide
are not completely scavenged in papillary carcinoma tissues, suggesting that these
substances affect some role in cell function of thyroid tumors.
Key words
Thyroid Hormone - Free Radical Scavenger - Thyroid Tumor - Graves' Disease
