[In vivo regulation by calcium of the thyroidal iodine metabolism and its modulation by sodium, in the rat (author's transl)].
In vivo experiments, in the rat, using diets deficient in calcium, or sodium or both ions, proved these cations to regulate the thyroidal iodine metabolism. Calcium enhanced iodine entry into the thyroid and the intrathyroidal iodine and T4 pools. T4 level in serum was also increased by calcium. Sodium enhanced iodine entry and secretion. The two cations have local regulatory functions on the thyroid gland and do not affect TSH levels in serum and the hypophysis. The effects of calcium and sodium are interdependent, sodium deficiency suppressed the effects of calcium and the effects of sodium were significantly limited by calcium deficiency. Results from chromatography of the thyroid extracts and data from the literature are compatible with the hypothesis of calcium enhancing iodine entry and accumulation into the thyroid gland mainly through an effect on exocytosis of thyroglobulin, the was this ion enhances exocytosis of protein in stimulus-secretion coupling. An addition to this theory is pur forward in order to reconcile with it the whole set of experimental data obtained with the two cations, in vivo and in vitro, on thyroidal iodine metabolism.
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002712:Chlorides / Q000494:pharmacology; D004032:Diet; D004039:Diet, Sodium-Restricted; D006801:Humans; D007455:Iodine / Q000378:metabolism*; D010902:Pituitary Gland / Q000032:analysis; D051381:Rats; D012964:Sodium / Q000502:physiology*; D013961:Thyroid Gland / Q000378:metabolism*; D013972:Thyrotropin / Q000032:analysis / Q000097:blood; D013974:Thyroxine / Q000097:blood
D002712:Chlorides; D013972:Thyrotropin; D007455:Iodine; D012964:Sodium; D013974:Thyroxine; D002118:Calcium
Régulation in vivo par le calcium du métabolisme thyroïdien de l'iode et sa modulation par le sodium, chez le rat.