Differences in prostaglandin E2, prostaglandin F2α and prostacyclin contents and their response to thyrotrophin stimulation and in prostaglandin-stimulated cyclic AMP response in normal and Graves's thyroid slices

: The human thyroid contained prostaglandin (PG) E2, PGF2 alpha and 6-oxo-PGF1 alpha, an end-metabolite of prostacyclin (PGI2), the 6-oxo-PGF1 alpha content being the highest of these prostaglandins. Graves's thyroid contained a significantly higher amount of PGF2 alpha and lower amounts of PGE2 and 6-oxo-PGF1 alpha than the normal thyroid. Thyrotrophin acutely augmented the thyroid contents of PGE2, PGF2 alpha and 6-oxo-PGF1 alpha. The TSH-stimulated increases in PGE2 and 6-oxo-PGF1 alpha were lower but the TSH-stimulated increase in PGF2 alpha 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 F2 alpha 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.