Thyroxine (symbol T4) is a hormone secreted by the thyroid gland into the bloodstream. Aside from being involved in metabolic activities, this hormone regulates the level of oxidation inside the cells.
Produced and secreted by the thyroid gland, thyroxine facilitates the regulation of the adrenal system. This hormone also has a role in normal growth, development and energy that are essential for maintaining a healthy body weight. In addition, thyroxine also helps to stabilize the mood. The thyroid gland actually produces two hormones, the other being triiodothyronine (T3). Both thyroxin (T4) and triiodothyronine (T3) are partially made up of iodine and created once the pituitary gland makes the thyroid-stimulating hormone (TSH). When either of these thyroid hormones is in excess in the body the condition is known as hyperthyroidism. On the other hand, if there is a deficiency of any of these hormones, the condition is known as hypothyroidism. Both these conditions can result in serious adverse consequences on the body.
Both the thyroid hormones are necessary for a healthy body. Any deficiency of these hormones in infants as well as adults may result in retarded growth and even lead to mental retardation. In several countries, infants regularly undergo thyroid check-ups to ensure that their thyroid gland is functioning normally. If the amount of thyroid hormones is low in an adult, he/ she may be facing several problems as the different systems in their body would not function as they should. They may suffer from suppressed metabolism, which may result in abnormal weight gain and their cardiac output as well as respiration may be poor.
Right from the beginning, it is important to study the effects of thyroxine on mental ailment and mood extensively. There are several evidences, which are increasing by the day that the functioning of the thyroid gland of people suffering from conditions such as bipolar disorder or major depression may possibly also be very poor. Findings of some laboratory tests also suggest that while treating low levels of thyroxine (T4) and triiodothyronine (T3) standard levels may not necessarily be correct. Hence, the degree of what is believed to be standard level of thyroid hormones has been changed a number of times. Hence, physicians are advised to no longer ignore the low thyroid readings, because such readings may be medically significant.
A blood test can be undertaken to detect whether the body is unsuccessful in making sufficient amount of thyroxine (T4). The preliminary thyroid test may be TSH test, which only evaluates and reveals the thyroid-stimulating hormone's level in the body. If the reading of the TSH test is not satisfactory, a physician may ask the patient to undertake thyroxine (T4) and triiodothyronine (T3) tests to know the exact levels of the two thyroid hormones in the body. If the level of thyroxine is found to be poor, the physician may recommend taking a supplement medicine called levothyroxine. This medicine is the synthetic variety of thyroxine (T4). You can find this medicine by it brand name is Synthroid®.
There are several evidences that suggest taking the supplement medicine levothyroxine may not as effectual as taking the brand name drug - Synthroid®. One reason behind this is possibly the unsteadiness of the various medicine version of thyroxine (T4). In fact, different formulations of synthetic thyroxine may have different functionality and many people often complain that they experience different problems after taking the generic versions of the hormonal drug. The problems are more and frequent when people change from one generic thyroxin drug to another, which are made by different pharmaceuticals. However, many people in the medical field still argue that generic thyroxine and Synthroid® are equally good and effectual. On the other hand, several physicians now seem to concur with the patients using thyroid medicine supplements that there is a world of difference between the generic drugs and Synthroid®.
While taking sufficient thyroxine medicine is very important, it is also important to ensure that one is not taking it in excess. This is because elevated levels of thyroxine in the body may result in sweating, weight loss, tremor and swelling on the neck in the place where the thyroid gland exists. Enduring hyperthyroidism for a prolonged period may lead to heart problems, hair loss and also osteoporosis. When a person is experiencing the symptoms related to elevated levels of the thyroid hormones, the main aim should be to reduce the thyroxin (T4) and triiodothyronine (T3) levels in the body. This can be achieved by getting rid of the thyroid gland and supplementing the thyroid hormones by taking levothyroxine. Alternatively, a person may also take medications that help in restraining the functioning of the thyroid gland.
As discussed above, thyroxine is a vital hormone for our body as it regulates the metabolic functions and also influences the functioning of various organs in our body.
Thyroxine is among the primary hormones that are released by the thyroid follicular cells. Inside our body, thyroxine works to regulate the metabolic process and also plays an important role in the synthesis of protein. This hormone is crucial to maintain a healthy growth as well as development in humans, because it is responsible for bone growth and also helps in the process involved in maturation of neurons. At the same time, thyroxine augments the catecholamine effect - which is the sensitivity of the body to adrenaline.
Thyroxine also helps to augment the basal metabolic rate, which is also known as BMR, in the body. Thyroxine influences the BMR, thereby helping it to increase. In other words, thyroxine is responsible for enhancing all metabolic activities in the body and, in this way; it contributes to production as well as proper use of energy. This, in turn, leads to an augmented BMR.
This thyroid hormone influences more or less all the systems in our body, such as the cardiovascular system, gastrointestinal (GI) system as well as the central nervous system. It also has effects on growth, development, bones and our reproductive system.
Thyroxine (T4) has a direct relation with the energy produced in our body. This hormone helps to produce energy by triggers and neutralizing the enzymes that are engaged in the metabolism of carbohydrates, proteins and fats.
Inside the liver, thyroxine works to enhance synthesizing of glucose to pyruvate, accelerates cholesterol release and aids in converting fats into sugar. Similarly, in our digestive system, the function of this thyroid hormone is to augment digestive juice secretion as well as promoting the functioning of the smooth muscles, thereby, making it easy for the contractions of the digestive tract to ensure smooth gastric mobility.
Thyroxine also has a vital role in the functioning of the cardiac muscles and skeletal muscles. This hormone not only helps the human body to develop normally, but also tones it and ensures that it functions normally.
Thyroxine also has a crucial part in the maturation of the bones as one gets older. In fact, this hormone facilitates the process.
As is evident from the above mentioned functions of thyroxine (T4), it is a versatile hormone having multifaceted roles in different parts of our body. For instance, it plays a vital part in ensuring that the body systems develop normally in younger persons. Additionally, this hormone also maintains this function all through the adulthood of an individual.
This hormone is also highly beneficial for the reproductive system, as it enhances the prospects of childbearing abilities of a woman and, at the same time, promotes breast milk secretion for the newborn to feed on. Thyroxine is also beneficial for our skin, as it keeps the skin well hydrated and promotes hair growth and secretions from the exocrine gland.
Thyroxine (T4) is produced in the thyroid gland and released into the bloodstream, following which blood transports this hormone to the cells. Only the hormones that are vigorous or are free and unattached are allowed into the cells. In fact, in the bloodstream, almost 99 percent thyroxine (T4) hormone is attached to proteins. Therefore, the concentration of free and unbound thyroxine hormone in the bloodstream is extremely crucial during medical examination as well as diagnosis.
Thyroxine affects the metabolic process in the body by controlling the amount of oxygen used by the cells and also by generating body heat. Inside the liver, thyroxine influences cellular respiration as well as the process involving transformation of oxygen and glucose into carbon dioxide and energy respectively. In fact, thyroxine's presence itself helps to encourage the initial stage of metabolism by transforming glucose to pyruvate. In the digestive system (stomach and the intestines), thyroxine supports the contraction of gastric muscles and secretion of digestive juices.
When the thyroid gland becomes either overactive or underactive, it may lead to several problems vis-à-vis the levels of thyroxine (T4) in the body. Having excessive thyroxine in the body results in a condition known as hyperthyroidism and it may cause weight loss, nervousness and other health issues that may turn out to be grave. On the other hand, when the thyroid gland is underactive and there is poor amount of thyroxine in the body, it may cause several other health problems, such as weight gain and developmental issues. People suffering from underactive thyroid gland may take supplements or undergo hormone therapy to ensure that the body gets normal supply of thyroxine and functions optimally.
Our body needs thyroid hormones to ensure that its cells develop normally. Thyroid hormones are essential for the body because they regulate fat and protein metabolism. Moreover, these hormones regulate a variety of physiological activities and, at the same time, assist in generating energy and body heat.
Animals also need thyroxine because this thyroid hormone is necessary during their hibernation period. In addition, thyroxine regulates the birds' molting behaviour.