Although the tissue TG content was greatly reduced, the hypothyroidism was mild with slow progression of the goiter, because the mutant TG was a relatively good substrate for the synthesis of the thyroid hormones.
The association of clinical and biological hypothyroidism with undetectable levels of serum thyroglobulin (Tg) and the presence of iodohistidines in the urine suggested the diagnosis of defective Tg gene expression.
To determine the mechanisms of manganese-induced hypothyroidism and understand how SLC30A10 and SLC39A14 cooperatively mediate manganese detoxification, here we produced <i>Slc39a14</i> single and <i>Slc30a10/Slc39a14</i> double knockout mice and compared their phenotypes with that of <i>Slc30a10</i> single knockouts.
To determine the mechanisms of manganese-induced hypothyroidism and understand how SLC30A10 and SLC39A14 cooperatively mediate manganese detoxification, here we produced <i>Slc39a14</i> single and <i>Slc30a10/Slc39a14</i> double knockout mice and compared their phenotypes with that of <i>Slc30a10</i> single knockouts.
In females, there was an ApoE allele effect on thyroid status (P < or = 0.01), E2 being negatively (P < or = 0.01) and E4 being positively (P < or = 0.05) associated with "hypothyroidism".
Also, we demonstrated that TRH Receptor 1 (TRH-R1) is colocalized in NEI immunoreactive neurons in the peduncular part of the lateral hypothalamus (PLH) and NEI precursor mRNA expression increased by hypothyroidism indicating that NEI neurons are responsive to the feedback mechanisms of the Hypothalamic Pituitary-Thyroid Axis (HPT).
Our results show that 6-n-propyl-2-thiouracil (PTU) treatment producing hypothyroidism induced a significant increase in the expression of PC1/3, PC2, and pro-TRH in the PVN and LH, but not VMN.
Due to case reports of thyroid dysfunction in 18q deletions and the well-established association between hypothyroidism and aneusomies, we undertook thyroid testing in all individuals and completed TRH studies on 50 of them.
The syndrome is characterized by: adipsia-hypodipsia (5/5 patients), recurrent hypernatremia (5/5), obesity (4/5), inability to excrete a water load (5/5), lack of growth hormone release in response to provocative stimuli (4/4), blunted thyrotropin releasing hormone responses (3/4), hypothyroidism (2/4), and hyperlipemia associated with hypernatremic crisis (1/1).
In addition, the absence of hypothyroidism and normal responsiveness of serum TSH to TRH and L-triiodothyronine administration in untreated family members suggest that the thyroid has compensated for the hormone resistance by increased secretory activity under the control of pituitary TSH secretion.
It is suggested that 1) among euthyroid relatives with a family history of Graves' disease, there are many with abnormalities in TRH responsiveness and T3 suppressibility, 2) nonsuppressible subjects are more likely to be TRH hyporesponders and vice versa, 3) hyperthyroidism or hypothyroidism occurs frequently in euthyroid relatives with a family history of Graves' disease, and 4) thyrotoxicosis occurs frequently in TRH-hyporesponders, and hypothyroidism occurs in the others.
However, an abnormally exaggerated TSH response to TRH was observed not only in the hypothyroid patients but also in six of the other subjects, indicating a decreased thyroid feedback at the pituitary level in the presence of a normal serum concentration of thyroid hormones.