Modulation of prostaglandin E 2, F 2α, I 2 content and synthesis by thyrotropin in cultured porcine thyroid cells and intact rat thyroid glands

Abstract

Porcine thyroid gland contains prostaglandin E 2, prostaglandin F 2α and prostacyclin (prostaglandin I 2) (measured as an end metabolite, 6-keto prostaglandin F 1α) and it contins more prostaglandin I 2 than prostaglandin E 2 or F 2α. Cultured porcine thyroid cells contain prostaglandin E 2, F 2α and I 2. When cultured in the presence of thyroid stimulating hormone (TSH), thyroid cells contain more prostaglandin I 2 than prostaglandin E 2 or F 2α but when cultured in its absence, they contain more prostaglandin E 2 or F 2α than prostaglandin I 2. Thyroid cells synthesize prostaglandin E 2, F 2α and I 2; when cultured in the presence of TSH, they synthesize more prostaglandin I 2 than prostaglandin E 2 or F 2α but when cultured in its absence, they synthesize more prostaglandin E 2 or F 2α than prostaglandin I 2. When cultured in the presence of TSH, thyroid cells take up iodide and organify it but when cultured in its absence, they do not take up iodide. When cultured in the presence of TSH, thyroid cells synthesize prostaglandin I 2 and take up iodide, indicating that in the physiological conditions, prostaglandin I 2 plays a more important role than prostaglandin E 2 or F 2α. Rat thyroid gland contains prostaglandin E 2, F 2α and I 2. Endogenous increase in serum TSH through goitrogen treatment and exogenous TSH administration augment prostaglandin I 2 contents and depress prostaglandin E 2 and F 2α contents. Suppression of endogenous TSH by thyroxine treatment depresses prostaglandin I 2 contents and augments prostaglandin E 2 and F 2α contents. Chronic exposure to TSH augments prostaglandin I 2 synthesis and depresses prostaglandin E 2 and F 2α syntheses but chronic nonexposure to TSH depresses prostaglandin I 2 synthesis and augments prostaglandin E 2 and F 2α synthesis in in vivo rat thyroid glands and in vitro cultured porcine thyroid cells.