Thyroid gland goiter

Each step in the synthesis of thyroid hormones is regulated by pituitary TSH. TSH stimulates the iodide pump, Tg synthesis, and colloidal uptalce by foUicular cells. TSH also regulates the rate of proteolysis of Tg for the fib-eration of T4 and T3 is also regulated by TSH. In addition, TSH induces an increase in the size and number of the thyroid foUicular ceUs. Prolonged TSH stimulation leads to increased vascularity and eventual hypertrophic enlargement of the thyroid gland (goiter). 

Low levels of iodine in the diet often lead to hypothyroidism and an enlarged thyroid gland (goiter). This condition has largely been eliminated by the addition of sodium iodide to commercial table salt. 

Thyroxine (see the model above ) is an aromatic compound and a key hormone that raises metabolic rate. Low levels of thyroxine (hypothyroidism) can lead to obesity, lethargy, and an enlarged thyroid gland (goiter). The thyroid gland makes thyroxine from iodine and tyrosine, which are two essential components of our diet. Most of us obtain iodine from iodized salt, but iodine is also found in products derived from seaweed, like the kelp shown above. An abnormal level of thyroxine is a relatively common malady, however. Fortunately, low levels of thyroxine are easily corrected by hormone supplements. After we study a new class of reaction in this chapter called electrophilic aromatic substitution, we shall return to see how that reaction is related to thyroxine in "The Chemistry of... Iodine Incorporation in Thyroxine Biosynthesis."... 

Thirty isotopes are recognized. Only one stable isotope, 1271 is found in nature. The artificial radioisotope 1311, with a half-life of 8 days, has been used in treating the thyroid gland. The most common compounds are the iodides of sodium and potassium (KI) and the iodates (KIOs). Lack of iodine is the cause of goiter. 

Iodine. Of the 10—20 mg of iodine in the adult body, 70—80 wt % is in the thyroid gland (see Thyroid and antithyroid preparations). The essentiahty of iodine, present in all tissues, depends solely on utilisation by the thyroid gland to produce thyroxine [51-48-9] and related compounds. Well-known consequences of faulty thyroid function are hypothyroidism, hyperthyroidism, and goiter. Dietary iodine is obtained from eating seafoods and kelp and from using iodized salt. 

Several nonoccupational health problems have been traced to cobalt compounds. Cobalt compounds were used as foam stabilizers in many breweries throughout the world in the mid to late 1960s, and over 100 cases of cardiomyopathy, several followed by death, occurred in heavy beer drinkers (38,39). Those affected consumed as much as 6 L/d of beer (qv) and chronic alcoholism and poor diet may well have contributed to this disease. Some patients treated with cobalt(II) chloride for anemia have developed goiters and polycythemia (40). The impact of cobalt on the thyroid gland and blood has been observed (41). 

Lithium is concentrated in the thyroid gland and can impair thyroid hormone synthesis. Although goiter is uncommon, as many as 30% of patients develop at least transiently elevated thyroid-stimulating hormone values. Lithium-induced hypothyroidism is not usually an indication to discontinue the drug. Patients can be supplemented with levothyroxine if continuation of lithium is desired.30... 

Goiter A nonmalignant enlargement of the thyroid gland, visible as a swelling at the front of the neck, that is often associated with iodine deficiency. 

I deficit, Mn excess In the Middle Volga regions Decreased I and increased Mn content in Podsoluvisols and Arenosols Disturbance of I exchange due to its deficit is enhanced by Mn excess. Endemic increase of thyroid gland and endemic goiter... 

Content of chemical elements and their ratios are close to optimum Phaerozems, Chernozems and Kastanozems. I deficiency is common in river valleys Content of many nutrients is optimal in soils and forage crops in some places, the I deficiency of P, K, Mn, and I occurs Endemic increase of thyroid gland and endemic goiter take place in Phaerozems and Floodplain soils... 

I, Co, Cu deficit Various mountain regions Carpathian, Caucasian, Crimea, Tien-Shan, etc Mountain soils Endemic increase of thyroid gland and endemic goiter, Cobalt-deficiency and B12 vitamin-deficiency... 

Demonstration that the effects of thyrotoxicosis or goiter are due to an excess or deficiency in (thyroxine + T3) secretion does not explain how the diseases originate nor why development and metabolic rate are affected. It is thought that some cases of thyrotoxicosis (Graves disease) may be caused by abnormal immune responses mimicking the effects of thyroid-stimulating hormone on the thyroid gland. 

Goiter enlargement of the thyroid gland as a consequence of inadequate dietary iodine. 

Hypothyroidism Goiter (enlarged thyroid gland), decreased reflexes, intolerance of cold weather, depression... 

Potassium iodide (KI) is added to table salt (known as iodized salt) to help prevent enlargement of the thyroid gland, a condition known as a goiter. 

Trace amounts of iodine are required for a healthy body. Iodine is part of the hormone thyroxin produced by the thyroid gland. Thyroid secretions control the physical and mental development of the human body. A goiter, a swelling of the thyroid gland, is caused by the lack of iodine. Adding thyroid medication and iodized salt to the diet helps prevent this disease. Radioactive iodine (1-131), with a half-life of eight days, is used to treat some diseases of the thyroid gland. 

Iodine takes part in the thyroid gland s hormone synthesis. Endemic goiter with hypothyreosis occurs under iodine deficiency as well as arterial hypertension. Iodine deficiency in pregnant women can cause... 

Diseases associated with thyroid glands are the result of either excess production of thyroid hormone (hyperthyroidism), or its insufficiency (hypothyroidism). Both cases can result in a goiter. 

In a hyperfunctioning of the thyroid gland, secretion of an excess quantity of thyroid hormones leads to a hyperthyroid condition (Basedow s disease, goiter). In this condition, drags are used that suppress production of thyrotropic hormones in the anterior lobe of the hypophysis (diiodotyrosine), in the thyroid gland (propylthiouracil, methylthiouracil,... 

Iodine is an essential nutrient element required for thyroid gland. It is added to salt and to animal feeds for the prevention of goiter. In medicine it is used as a therapeutic reagent for the treatment of various thyroid-related diseases. It also is used as an antiseptic. Radioactive isotopes of iodine are used for treating thyroid cancer, heart diseases including tachycardia, and as a tracer for diagnosing certain diseases. 

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