The Effect of Iodine on the thyroglobulin Synthesis in Cultured Porcine Thyroid Cells
- Author:
Eun Jig LEE
;
Hyun Chul LEE
;
Kap Bum HUH
;
Kyung Rae KIM
;
Sung Kil LIM
;
Kyung Mi LEE
- Publication Type:Original Article
- Keywords:
Thyroglobulin synthesis;
Iodide;
Porcine thyroid cell
- MeSH:
Colloids;
Egtazic Acid;
Homeostasis;
Iodine;
Methimazole;
Pituitary Gland;
Thyroglobulin;
Thyroid Gland;
Trypsin
- From:Journal of Korean Society of Endocrinology
1994;9(4):318-324
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The amount of thyroglobulin synthesized from thyroid cells and stored in colloid space in very important in thyroid hormone synthesis. The thyroglobulin synthesis is mainly regulated by TSH secreted from the pituitary gland. But recently there were some reports about the possibility that iodine regulated the thyroid protein synthesis. So our studied were conducted to determined whether iodine could have inhibitory effect on thyroglobulin synthesis and methimazole could abolish the inhibitory effect of idoine.Porcine thyroid cells were isolated by sequential trypsinization in the presence of EGTA, seeded at high density(1X10^6 cells/cm^2) and cultured. One week later, Nal was added in different concentrations(10^-7, 10^-6, 10^-5, 10^-4M). 24hour medias were collected and checked the amount of thyroglobulin secreted. And also pulse-labeling were performed with[^35S] cysteine/methionine(1-2 uCi/well) for 1 hour at the same conditions. We used 3mM methimazole and 10^-4M NaI to observe the blocking effect of methimazol in iodine.The extracellular thyroglobulin secretion was significantly decreased by iodine in dose dependent manner(82.4%, 80.7%, 76.8% and 73.1% of control). And also intracellular thyroglobulin synthesis was significantly decreased by iodide in dose dependent manner(100.5%, 83.4%, 82.3% and 79.4% of control). The inhibitory effect of iodide was abolished by methimazole(74.7% to 101.3% of control). These data indicate that high iodide inhibit the thyroglobulin synthesis and secretion from the thyroid cells, and furthermore autoregulation by iodide may include thyroglobulin synthesis. And also this effect is dependent on the generation of an organic form of iodine because methimazole abolish the inhibitory effect of iodide.
