Vulsma et al (28) showed that the umbilical cord level of [T.sub.4] in fetuses with congenital hypothyroidism due to a total
organification defect or thyroid agenesis was 30% to 60% that of normal fetuses, suggesting that maternal input of [T.sub.4] continues until birth.
In 1948, Wolff and Chaikoff showed that receiving a large amount of iodide stopped the
organification of the thyroid cells in rats [7].
Maternal-fetal transfer of thyroxine in congenital hypothyroidism due to a total
organification defect or thyroid agenesis.
In the colloid, thyroid peroxidase covalently incorporates transported iodide into tyrosine residues of the thyroid hormone precursor, thyroglobulin, in a process known as
organification (30,3).
Within the follicular lumen, thyroid peroxidase (TPO) oxidizes iodine and then catalyzes the
organification of tyrosine residues in thyroglobulin.
This leads to a reduction in thyroid hormones synthesis, which make the cells defective in thyroid iodine
organification. Therefore, T cells, in addition to having cytotoxic activity to thyroid epithelial cells, also stimulate B cells to produce anti-thyroid antibodies (anti-TPO, anti-TG and antirreceptor antibody TSH) [24,32,36,45].
After entering the thyroid, iodite is transported to the apical membrane, where it is oxidized in an
organification reaction that involves thyroid peroxidase (TPO), thyroid oxidase (ThOx) and hydrogen peroxide ([H.sub.2][O.sub.2]).
In addition, the
organification degree of oleic acid-coated Ti[O.sub.2] was determined as 2.96%, further validating successful preparation of oleic acid-coated Ti[O.sub.2].
Thyroid peroxidase (TPO) is a membrane-bound glycosylated hemoprotein that has a key role in the biosynthesis of thyroid hormones by
organification. Iron deficiency has been reported to impair the body's ability to make its own thyroid hormone, which could increase need for thyroid medication.
The "
organification" of functional GI disorders: implications for research.
It has been shown that purified hCG increases iodide uptake, increases cyclic-AMP production dose dependently and stimulates
organification and [T.sub.3] secretion.