Traditional Chinese Medicine Approach to Hypothyroidism

Abstract

cell to release the thyroid hormones. Scattered around the outside of the follicles are parafollicular cells, which produce a hormone calcitonin. There are two different thyroid hormones 3, 5, 3', 5'-/-tetraiodothyronine, also known as thyroxin (T4), and in lesser amount of 3, 5, 3'-/-triiodothyronine (T3). 3 Thyroid hormones are unique in the way they utilize iodine into their structure. The tyrosine residues in thyroglobulin are iodinated to form mono-or diiodotyrosine, which are combined to form T3 and T4. One molecule of T4 contains four iodine atoms, and one molecule of T3 contains three iodine atoms. Plasma levels of T4 and T3 are 0,4% and 0,04% respectively. 2 Thyroid hormones are essential for promotion of growth and development, especially in children, and maintenance of body's homeostasis by regulation of energy production and heat generation. Thyroid gland is unique in the way it stores the considerable amounts the synthesized hormones before secreting them, none of the other endocrine glands store their hormones in another form for later release. When they are to be released, T3 and T4 detach from the thyroglobulin and enter the blood stream. In the blood, however, they are transported by plasma proteins and circulate as a hormone-globulin complex. Although the thyroid gland produces more T4 than T3, T3 has higher affinity to the thyroid hormone receptor. Thus, the small amount of T4 that enters target tissues is usually converted to T3 which is considered a principal thyroid hormone. Thyroid hormones helps regulate the metabolic rate of all cells, as well as the processes of cell growth and tissue differentiation. There are several control mechanisms of the thyroid function. The classic hypothalamic-pituitary-thyroid axis is the primary control mechanism in which the pituitary synthesis and release of thyroid-stimulating hormone (TSH) is stimulated by the release of thyrotropin-releasing hormone (TRH) from the hypothalamus, TSH in turn stimulates growth and hormone secretion of the thyroid gland. Secondary mechanisms of thyroid function control include: "up-regulation" and "down-regulation" of pituitary and peripheral deiodinase expression, to modify the effects of T4 and T3; or thyroid gland auto-regulation in response to iodine availability. Hypothyroidism Hypothyroidism is defined as inadequate peripheral tissues stimulation by the thyroid hormone. This deficiency is caused by either failure in adequate thyroid hormone production or reduction in tissue sensitivity to the thyroid hormone stimulation. The decreased thyroidal secretion of thyroid hormone, due to the factors affecting the thyroid gland itself is called "primary" hypothyroidism; decrease in serum concentrations of thyroid hormone caused by an inadequate TSH secretion, due to factors directly affecting the anterior pituitary gland is called "secondary" hypothyroidism; the failure of TRH release, due to the factors affecting hypothalamus, will cause an indirect decrease in the secretion of thyroid hormones called "tertiary" hypothyroidism. The secondary and tertiary hypothyroidism is often referred to as "central hypothyroidism." Hypothyroidism with onset in adulthood causes a generalized slowing down of the organism, with deposition of glycosaminoglycans in intracellular spaces, particularly in skin and muscle, producing the clinical picture of myxedema. Hypothyroidism is graded on a scale ranging from Grade 1-mild cases in which the individual hardly notices signs and symptoms thyroid hormone deficiency, to Grade 3-severe cases in which severe unregulated thyroid insufficiency may cause myxedema coma and death. Most symptoms of hypothyroidism in adults are largely reversible with therapy. Traditional Chinese medicine approach to hypothyroidism Traditional Chinese medicine has for several thousand years been the treatment of choice for over a quarter of the world's population for its ailments, infections, and other health problems. Today, Traditional Chinese Medicine (TCM) is practiced in China alongside with Conventional Western Medicine. Most hospitals include departments