The thioureylene drugs, propylthiouracil and methylmercaptoimidazol(MMI), exert their antithyroid effect primarily through inhibition of thyroid peroxidase-catalyzed iodination of thyroglobulin. Recently the interest about the effect to the
thyroglobulin synthesis of these drugs have been increasing. So we studied the MMI effect to the thyroglobulin synthesis in cultured porcine thyroid cells.
Porcine thyroid cells were isolated by sequential trypsinization in the presence of EGTA, seeded at high density(1×106 cells/㎠) and cultured. One week later, MMI was added in different concentrations(0,02, 1, 5mM)with TSH only or with 4H(b-TSH,
Insulin, Transferrin, hydrocortisone) or without hormone, Medias were collected after 24 hours and compared the amount of thyroglobulin secreted. And also pulse-labeling were performed with S35 cysteine/methionine(1-2uCi/well) for 30, 60, 90min.
at
the
same conditions.
There was no significant change in the amount of the secreted thyroglobulin by MMI, and there was no significant change in the pulse-labeled intracellular thyroglobulin by MMI. And also there was no significant change in the secretion of
TSH-stimulated
thyroglobulin by MMI.
So we conclude that MMI has no effect on the thyroglobulin synthesis in cultured porcine thyroid cells and also MMI has no effect on the TSH-stimulated thyroglobulin synthesis in cultured porcine thyroid cell. (J Kor Soc Endocrinol 9: 332-336,
1994)
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