The human thyroid contained prostaglandin (PG) E2, PGF2α and 6-oxo-PGF1α, an end-metabolite of prostacyclin (PGI2), the 6-oxo-PGF1α content being the highest of these prostaglandins. Graves's thyroid contained a significantly higher amount of PGF2α and lower amounts of PGE2 and 6-oxo-PGF1α than the normal thyroid. Thyrotrophin acutely augmented the thyroid contents of PGE2, PGF2α and 6-oxo-PGF1α. The TSH-stimulated increases in PGE2 and 6-oxo-PGF1α were lower but the TSH-stimulated increase in PGF2α was significantly higher in Graves's thyroid than in the normal thyroid. Prostaglandin E2 and PGI2 stimulated human thyroid cyclic AMP synthesis, with the magnitudes of PGE2-and PGI2-stimulated increases in cyclic AMP being equal in normal and Graves's thyroid. Prostaglandin E2α did not stimulate cyclic AMP synthesis significantly.
These results provide evidence that prostaglandins play important roles in thyroid physiology and the pathophysiology of Graves's disease.
