Adrenocorticotropin (also adrenocorticotropic hormone, or ACTH for short) is better known as the “stress hormone” because the body secretes it especially in stressful situations. ACTH is produced in the anterior pituitary of the brain, and is produced when corticotropin-releasing hormone (CRH), which is superior to ACTH, stimulates the anterior pituitary to do so. ACTH stimulates the adrenal cortex to produce various hormones, including several sex hormones.
What is adrenocorticotropin?
Schematic diagram showing the anatomy and structure of the endocrine (hormone) system. Click to enlarge. ACTH is a hormone produced in the anterior pituitary gland. It is secreted to a greater extent in situations in which a person experiences stress. Possible stress-triggering factors can be injury, illness, general life circumstances (work, school), or strong emotions. For example, tear fluid shows high levels of ACTH due to emotional crying. Because of the clear relationship between stress and ACTH concentration in the blood, ACTH is colloquially referred to as the stress hormone.
Production, manufacture, and formation
ACTH is produced in the anterior pituitary gland of the brain. However, the anterior pituitary requires a stimulus in the form of a release of CRH to produce ACTH. As a result of the release of ACTH, the adrenal cortex in turn now begins to release mineralocorticoids, glucocorticoids and sex hormones. Mineralocorticoids are needed by humans to regulate potassium–sodium balance, glucocorticoids to maintain glucose metabolism, and sex hormones – roughly speaking – for reproduction and sex drive. If a person is not exposed to stress, the concentration of ACTH decreases throughout the day, so that in the evening just before falling asleep only a very low ACTH concentration is detectable. If a person is exposed to a permanent stress situation – such as an illness or an unsatisfactory work situation – the concentration of ACTH is continuously high. Poor falling asleep and sleeping through the night is the result. In newborns, the ACTH secretion of the brain has not yet adjusted. A high concentration of ACTH in the evening may contribute to unsatisfactory sleep onset at this stage of life.
Function, effects, and properties
ACTH is an endogenous hormone produced in the anterior pituitary gland. It provides for the release of various hormones from the adrenal cortex, such as sex hormones and hormones to maintain potassium/sodium and glucose balance. A short-term very high release of ACTH in a stressful situation – such as an attack on one’s person – triggers ACTH in close interaction with the better known adrenaline to escape or counterattack. In such a situation, the person has a feeling of “superhuman strength,” which can be essential for survival in coping with the situation. Various disorders of the body or of ACTH secretion can greatly affect a person’s daily life, such as when sleep disorders occur or the patient is constantly tired. ACTH imbalance is difficult to diagnose because the symptoms can also occur in conjunction with countless other diseases.
Diseases, complaints, and disorders
Numerous diseases and ailments can result in ACTH over- or under-function. Severe cold, stress, adrenal insufficiency can lead to increased secretion of ACTH. The person then experiences increased stress, has difficulty resting and, in the worst case, suffers from sleep disorders. Cushing’s disease refers to a tumor of the pituitary gland that mainly damages the ACTH-producing cells and stimulates them to produce more ACTH. As a result, the adrenal gland produces increased cortisol, which in turn can lead to complaints (such as metabolic disorders, expression of a moon face). If Sheehan’s syndrome is present – for example, as a reaction to a previous delivery – the pituitary gland produces too little ACTH. The symptoms are usually sexual aversion, lack of milk supply, and increased pallor. Patients suffering from ACTH deficiency often feel tired and fatigued despite sufficient rest and sleep. ACTH imbalance can be difficult to diagnose and will only be detected by extensive blood testing.ACTH is often used to treat various forms of epilepsy. Patients suffering from West syndrome – a special form of epilepsy – respond particularly well to treatment with ACTH. Why the administration of ACTH has a mitigating effect has not yet been adequately explained, but treatment with ACTH is now standard practice; about 8 out of 10 children are initially seizure-free after administration of ACTH. Seizures recur in 65% of treated children after discontinuation of ACTH. Despite the good prognosis, the use of ACTH to treat epilepsy is not without controversy, as severe side effects can sometimes occur. Side effects include general weakening of the immune system, high blood pressure and vomiting, gastric bleeding, heart failure, and leukocytosis. Premature infants usually do not respond to treatment with ACTH.
