Hormone production is localized in different parts of the body. The endocrine system includes hormone-producing organs such as the pineal gland, thyroid gland, parathyroid glands, pituitary gland, thymus, pancreas, ovaries, testes, and adrenal glands.
What is hormone production?
Most hormone production takes place in the endocrine organs. Most hormones are produced in the pituitary gland, hypothalamus, and adrenal glands. Most of the hormone production takes place in the endocrine organs. Most hormones are produced in the pituitary, hypothalamus, and adrenal glands. However, the pineal gland, parathyroid glands and islets of Langerhans of the pancreas also produce vital hormones. The endocrine glands also include the Leydig cells in the testis, the corpus luteum, and the cells of the heart that produce atrial natriuretic peptide (ANP). Hormones are even produced in organs that are not actually part of the endocrine system. For example, a variety of digestive hormones are produced in the stomach or intestine. Depending on the hormone, different starting substances are required for production. Glucocorticoids, mineralocorticoids and sex hormones are formed from steroids. The thyroid hormones T3 and T4 are based on iodine compounds. Adrenaline, noradrenaline, histamine, serotonin and melatonin are produced from amino acids. All releasing and inhibiting hormones, antidiuretic hormone (ADH), FSH, ACTH, LH, insulin, gastrin, parathyroid hormone, and erythropoietin are composed of peptides and proteins. Eicosanoids are the basis of prostaglandins and leukotrienes.
Function and role
The superior organ in hormone production is the hypothalamus. It produces eight hormones essential for life. With thyrotropin releasing hormone (TRH), the hypothalamus regulates thyroid activity via the pituitary gland. When TRH levels are high, the pituitary gland produces thyroid-stimulating hormone (TSH). This has a stimulating effect on thyroid growth and stimulates the release of the thyroid hormones T3 and T4. T3 and T4 are produced by the follicular epithelial cells. For this purpose, the cells require iodine. In the body, the thyroid hormones then cause energy mobilization and stimulation of metabolism. Corticotropin releasing hormone (CRH) is also produced in the hypothalamus. In the anterior pituitary, it ensures the release of the hormone ACTH. ACTH, the adrenocorticotropic hormone, is formed from 39 amino acids. It reaches the adrenal cortex via the bloodstream and stimulates the production of glucocorticoids there. Glucocorticoids belong to the steroid hormones. The starting substance is cholesterol, which either comes from food or is synthesized by the liver. Cortisol is then produced via the intermediate stages pregnenolone, progesterone, hydroxyprogesterone and deoxycortisol. The production of glucocorticoids is subject to circadian fluctuations. During sleep, hardly any glucocorticoids are produced, with maximum production in the early morning hours. Glucocorticoids such as cortisol stimulate glucose production and fat mobilization. At the same time, they inhibit the secretion of insulin. Insulin is produced in the beta cells of the pancreas. Production is stimulated in particular by food intake. After food intake, the insulin level in the blood rises so that more glucose can be transported from the blood into the cells. Another hormone produced in the hypothalamus is gonadotropin releasing hormone (GnRH). It stimulates the production and release of two gonadotropins in the anterior pituitary. The first is increased synthesis of FSH. FSH is the follicle-stimulating hormone. It reaches the gonads via the bloodstream. LH, luteinizing hormone, also affects the ovaries and testes. In men, LH stimulates testosterone production. In women, LH stimulates the production of estrogens in the ovaries.
Diseases and disorders
Hormone production can be disturbed in the various endocrine organs, causing a wide variety of symptoms. Most often, hormone production is disturbed in the subordinate endocrine organs. Rarely, benign or malignant diseases of the hypothalamus or pituitary gland disrupt hormone production. Thus, pituitary tumors may be hormone active or hormone inactive. The most common pituitary tumor is prolactinoma. This is a tumor that produces the hormone prolactin.Conversely, hormone production can also be restricted by the tumor, resulting in a growth hormone deficiency, for example. This is manifested by increased fat deposits on the abdomen, by an increased risk of osteoporosis or by a decrease in muscle mass. If the pituitary gland stops producing TSH, hypothyroidism develops with symptoms such as fatigue, exhaustion, cold intolerance, constipation and hair loss. A disturbance of hormone production in the adrenal gland also has drastic effects. A complete loss of production occurs in the so-called Addison’s crisis. Addison’s crisis usually develops from Addison’s disease. The sudden drop in hormone levels causes severe cardiovascular disorders that can even lead to coma. If Addison’s crisis is treated too late, it can be fatal. In Cushing’s disease, the problem is not a lack of hormone production, but an excess of it. In Cushing’s disease, a tumor of the pituitary gland produces too much ACTH. As a result, the adrenal cortex synthesizes too much cortisol. The disease is therefore also called hypercortisolism. Typical symptoms of Cushing’s syndrome are truncal obesity, weight gain, a round moon face, a reduction in muscle mass, increased blood pressure, impotence and, in children, growth retardation or obesity. If the pituitary gland produces too little antidiuretic hormone, the result is diabetes insipidus. Patients can no longer retain water in the body and excrete up to 20 liters of urine daily. They are constantly thirsty and drink large quantities. In Schwartz-Bartter syndrome, the pituitary gland produces significantly too much ADH. There is loss of appetite, vomiting, diarrhea, muscle cramps, and nausea due to electrolyte shifts. Causes of Schwartz-Bartter syndrome include trauma, brain inflammation, or severe burns. Pneumonia can also cause this syndrome.
