these results suggest that , in the incubation of thyroid slices , iodine atoms are preferentially incorporated into newly synthesized , less iodinated thyroglobulin , rather than preformed thyroglobulin , and that the iodination occurs , at least to a certain degree , in apical vesicles before the thyroglobulin is secreted into the colloid lumen .
C0040132
thyroid
C0040123
thyroglobulin