Ceruloplasmin and vitamin E levels in toxic multinodular goiter

Oxidation Products and Antioxidant Markers in Plasma of Patients with Graves' Disease and Toxic Multinodular Goiter: Effect of Methimazole Treatment

Oxidative stress plays an important role in hyperthyroidism-induced tissue damage, as well as in development of autoimmune disorders. To clarify influence of thyroid metabolic status and autoimmune factors on blood extracellular indices of reactive oxygen species (ROS) generation and free radical scavenging in hyperthyroidism, we studied patients with newly diagnosed and untreated Graves' disease without infiltrative ophthalmopathy (17 female and 8 male, aged 41.8 +/- 8.9) and toxic multinodular goiter (15 female and 9 male, aged 48.4 +/- 10.1) under the same antithyroid treatment protocol. Initially and after achievement of stable euthyroidism with methimazole, plasma levels of hydrogen peroxide (H202), lipid hydroperoxides (ROOH) and ceruloplasmin (CP) and serum concentrations of thiobarbituric acid-reacting substances (TBARS) were determined. Similarly, activities of plasma superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) were assayed. The results were compared to those of age- and sex-matched controls. Average duration of hyperthyroidism and treatment period were similar in both patients groups. H202, ROOH and TBARS concentrations were significantly higher in hyperthyroid patients compared to controls. Hyperthyroidism caused an evident increase in SOD and CAT activities and CP level, as well as a decrease in GPx and GR activities. Achievement of euthyroidism resulted in normalization of all analyzed parameters in both hyperthyroid patients groups. These findings suggest that the changes in blood extracellular indices of oxidative stress and free radical scavenging in hyperthyroid patients are influenced by thyroid metabolic status, and are not directly dependent on autoimmune factors present in Graves' disease.

Oxidative stress peripheral parameters in Graves' disease: the effect of methimazole treatment in patients with and without infiltrative ophthalmopathy

OBJECTIVES

The study was designed to estimate the influence of hyperthyroidism and antithyroid treatment on oxidative stress peripheral parameters in Graves' disease patients with and without infiltrative ophthalmopathy.

DESIGN AND METHODS

Free radical generation and scavenging plasma indices were determined in 47 patients with hyperthyroidism due to Graves' disease (22 with and 25 without infiltrative ophthalmopathy), as well as in 24 healthy volunteers after euthyroidism achievement with methimazole.

RESULTS

In the hyperthyroid patients, hydrogen peroxide, lipid hydroperoxides, thiobarbituric acid-reacting substances, ceruloplasmin, superoxide dismutase, and catalase were increased. Glutathione peroxidase and glutathione reductase, however, were reduced. Methimazole treatment resulted in all markers being normalized in the patients without infiltrative ophthalmopathy, yet oxidative stress was still present in the ophthalmopathy group.

CONCLUSION

We suggest that apart from the thyroid metabolic status influence, it is orbital inflammation that triggers changes in blood extracellular indices of reactive oxygen species metabolism.

Erythrocyte, plasma, and serum antioxidant activities in untreated toxic multinodular goiter patients

Erythrocyte, plasma, and serum antioxidant activities were studied in patients with newly diagnosed and untreated toxic multinodular hyperthyroid goiter and compared to healthy control subjects. Erythrocyte antioxidant enzyme activities, glutathione, malondialdehyde, and ceruloplasmin levels were significantly increased, whereas serum vitamin E, plasma vitamin C, and selenium levels were decreased in hyperthyroid patients compared to control subjects. The findings show that untreated toxic multinodular goiter causes profound alterations in components of the antioxidant system in erythrocytes indicative of increased oxidative stress. Taken together, these data suggest that hyperthyroid patients may benefit from dietary supplements of antioxidants.

Free radical activity and antioxidant defense mechanisms in patients with hyperthyroidism due to Graves' disease during therapy

Free radical-mediated oxidative stress has been implicated in the etiopathogenesis of several autoimmune disorders. We investigated the prooxidant-antioxidant status in order to evaluate the possible deleterious role of oxidative phenomena in patients with Graves' disease. Thirty patients with hyperthyroidism due to Graves' disease were investigated. Thirty age-matched healthy subjects were studied as a control group. Free radical activity indices, antioxidant defense systems, and thyroid and pituitary hormone levels were measured in fasting blood samples. Blood samples were taken before initiation of therapy and after attainment of euthyroid state. A significant increase in lipid peroxidation activity indices, i.e., conjugated dienes and thiobarbituric acid-reacting substances, was found in blood serum of the patients with untreated Graves' disease. These changes were accompanied by a decrease in plasma thiol and erythrocyte lysate thiol groups concentrations. Hyperthyroidism resulted in a marked increase in intracellular antioxidant enzymes, i.e., superoxide dismutase, catalase and glutathione peroxidase activities as compared to the controls. Extracellular anti-free radical scavenging systems potential, measured by glutathione reductase activity and total antioxidant status level, was found to be significantly decreased in untreated Graves' patients. Treatment with thiamazole resulted in normalization of the free radical and antioxidant activity indices. The obtained results indicate an enhanced generation of reactive oxygen species and impairment of cellular and extracellular antioxidant systems potential in patients with Graves' disease. The attainment of euthyroid state led to an improvement in oxidative stress indices and antioxidant potential parameters.

Effects of propylthiouracil treatment on antioxidant activities in blood of toxic multinodular goiter patients

Erythrocyte, serum and plasma antioxidant activities and the effects of propylthiouracil (PTU) treatment on these activities were studied in patients with toxic multinodular goiter. The activities of the erythrocyte antioxidant enzymes (glucose-6-phosphate dehydrogenase, catalase, Cu/Zn-superoxide dismutase, selenium (Se)-dependent glutathione peroxidase and glutathione reductase) and the levels of erythrocyte Se, serum ceruloplasmin and plasma malondialdehyde were significantly higher while serum vitamin E, plasma vitamin C and plasma Se were lower in hyperthyroid patients. PTU treatment, not for 1 but for 3 months caused a partial reversal of antioxidant activities to euthyroid levels. It is suggested that alterations in blood antioxidant activities following PTU treatment might be due to the antioxidant and/or antithyroid effect of this drug.