[Stimulatory effect of prostaglandins on biosynthesis of thyroid hormones and plasma TSH levels in the rats (author's transl)].
It is now postulated that prostaglandins (PG) are widely distributed in mammalian tissues and stimulate adenyl cyclase-cyclic AMP system in various organs. The present study was undertaken in an attempt to clarify the effect of PG on pituitary-thyroid axis in vivo. Rats were maintained on a low-iodine diet for 8 days. The animals received graded doses (10-500 mug) of PGE1, PGE2 and PGF2alpha ip daily from day 5 to the day of autopsy. The 4-hr thyroid 131O uptake was consistenly higher in 10 mug PGE1, 10 mug PGE2 and 100 mug PGF2alpha-treated rats than in the controls. Higher T3/T4 ratios were found in the diagested thyroids of PG-tristration. However, a single injection of PG did not affect thyroid 131I uptake in iodine-deficient animals. No change in the thyroid 131I uptake was found in iodine-replete rats chronically treated with PG. The increase in plasma TSH levels during treatment with 30 mug PGE1 and PGE2 was clearly shown. A similar result was also obtained with 100 mug PGF2alpha. The increase in thyroid 131I metabolism produced by the repeated administration of PG in iodine-deficient rats is due presumably to the direct stimulation on the thyorids of rats. In addition, PG elevated plasma TSH levels in such animals, probably mediated through the hypothalamic-pituitary system.
D000818:Animals; D008297:Male; D011453:Prostaglandins / Q000494:pharmacology*; D011458:Prostaglandins E / Q000494:pharmacology; D011460:Prostaglandins F / Q000494:pharmacology; D051381:Rats; D013268:Stimulation, Chemical; D013963:Thyroid Hormones / Q000096:biosynthesis*; D013972:Thyrotropin / Q000097:blood*; D013974:Thyroxine / Q000096:biosynthesis / Q000097:blood; D014284:Triiodothyronine / Q000096:biosynthesis
D011453:Prostaglandins; D011458:Prostaglandins E; D011460:Prostaglandins F; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine