Thyroxine is one of the most important hormones in the human body. Hormones are a series of substances that are synthesized in the glands, and whose main function is to maintain homeostasis or balance in our organism. Unfortunately, a number of diseases are associated with these drugs.
Most conditions are due to an error in the synthesis or release processes. This will consequently change the concentration in the blood and they will not perform their function properly.
What is thyroxine?
Also known as tetraiodothyronine or T4, thyroxine is a hormone made from iodine, which is synthesized and released from a gland located in the back of the throat. It has a special chemical structure, composed of the condensation of the amino acid tyrosine and the addition of 2 atoms of iodine.
The amount of T4 produced in this gland is much larger than other synthesized hormones, but it is not very biologically active. Several studies have established that thyroxine behaves as a peripheral prohormone, ie that it must be transformed into its active form by enzymatic action.
The hypothalamus and pituitary gland regulate the secretion of tetraiodothyronine. Both structures synthesize substances that are able to stimulate or inhibit the release of T4, depending on the requirements of the organism.
Which gland is responsible for the production of thyroxine?
The thyroid gland is responsible for the production and release of thyroxine in the blood. It is located at the back of the neck, just below the larynx, and in front of the trachea. The anatomy of the thyroid gland is similar to a shield: it consists of two lobes on each side of the trachea, and connected to a central area called the isthmus.
Under normal conditions, this gland weighs about 20 grams and is usually not palpable. The main function is the production of various hormones, among which T4 or thyroxine and T3 or triiodothyronine are the most important.
Specialized structures in the thyroid gland called follicles are responsible for synthesizing thyroid hormones. At the center of these follicles is a colloidal substance that contains everything necessary for hormone production. As such, the colloid contains enzymes, iodine, tyrosine and a special protein: thyroglobulin.
What is the function of this hormone?
The main function of thyroid hormones is related to the metabolism and growth of the human body. However, thyroxine is less biologically active and has a longer half-life than triiodothyronine. These properties make T4 the ideal drug to maintain a constant reserve.
In general, triiodothyronine is the active form of thyroid hormones, while thyroxine acts as the plasma reserve. When the body has low levels of T3, various enzymes in the peripheral tissue extract an iodine atom from thyroxine and convert it to its active form.
Studies have established that thyroid hormones play a very important role, even from the beginning of life in the womb. They are important for regulating the development and growth of people. In this context, they have the following functions:
- Promoting cognitive development
- Regulation of cellular metabolism
- They help with energy production
- Maintaining the function of the musculoskeletal system
- They participate in bone metabolism
- They alter the function of the cardiovascular and digestive systems
Diseases associated with thyroxine deficiency
The most common condition associated with thyroxine and triiodothyronine deficiency is hypothyroidism. This is a disease that is defined by reduced thyroid hormone effect at the tissue level. The most common cause is a reduction in the production or release of thyroid hormones, although it can also develop due to peripheral resistance.
Hypothyroidism can be primary or secondary. It is called primarily when there is a dysfunction in the gland itself, and central or secondary when reduced secretion of the release factors occurs at the level of the pituitary gland or hypothalamus.
The main causes of hypothyroidism include the following:
- Hashimoto’s disease
- Radiation therapy and certain medications
- Too much or too little iodine in the body
Deficiency of thyroid hormones can cause another condition called goiter, which is an increase in the size of the thyroid gland. This volume increase takes place so that it can capture more iodine and increase production.
Diseases related to excess thyroxine
Excess thyroxine and triiodothyronine in the blood are known as hyperthyroidism. It can be due to a number of conditions that change the function of the gland and increase hormone production.
Among the major diseases that can cause hyperthyroidism are the following:
- Graves-Basedow disease
- Toxic multinodular goiter
- Toxic adenoma
This condition can increase the basal metabolism in the human body, so that all the functions of the organism accelerate. As a result, the sufferer may experience palpitations, nervousness, weight loss and increased sweating.
Pregnancy can also lead to an increase in thyroid hormone levels, especially in the first trimester. However, this increase is physiological.
Thyroxine: an important hormone for the body
Thyroxine is a hormone produced in the thyroid gland that can be transformed into its active form in peripheral tissue, which means that it is a reserve source. Thyroid hormones perform important functions in the body, almost all of which are related to the regulation of basal metabolism and growth.
Diseases associated with excessive or lack of thyroxine alter basal metabolism and cause unpleasant and dangerous symptoms. Of course, timely diagnosis and treatment of these diseases will ensure proper treatment and prevent complications.