Circulating prostacyclin and thromboxane in patients with Graves' disease

We measured plasma levels of PGI2 as 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane A2 (TXA2) as thromboxane B2 (TXB2) in patients with Graves' disease and in normal subjects. The levels of plasma 6-keto-PGF1 alpha were significantly elevated and correlated with those of serum T4 and T3, respectively, in hyperthyroid patients with Graves' disease. Significant reduction of 6-keto-PGF1 alpha levels was observed after antithyroid drug therapy. In contrast, the levels of plasma TXB2 were significantly lower in untreated patients with Graves' disease than in normal subjects. These data suggest that an elevation of plasma 6-keto-PGF1 alpha may play some additional role in pathophysiology of Graves' disease.