Increased Erythrocyte Catalase Activity in Patients with Hyperthyroidism

Summary

Levels of human erythrocyte catalase activity were determined in 38 patients with thyroidal dysfunction. In patients with hyperthyroidism, erythrocyte catalase activities were found to be higher than the levels of normal subjects (P < 0.001). In hypothyroidism, erythrocyte catalase activities were of the same order as those of normal subjects. Significantly high positive correlation was found between erythrocytes catalase activity and the levels of thyroxine (r = 0.5794, n=36, P < 0.001), and slight positive correlation was detected between catalase activity and the levels of triiodothyronine (r = 0.3978, n=33, P < 0.05). A decreased erythrocyte catalase activity was observed when erythrocytes lysate was incubated with thyroid hormones. It was suggested that erythrocyte catalase activity had close relationship with thyroid state, however, direct effect of thyroid hormones were not observed on erythrocyte catalase assay system in vitro.

Key-Words

Catalase - Erythrocyte - Thyroxine - Triiodothyronine - Humans - Hyperthyroidism