Adrenocorticotropic hormone (行動), also known as corticotropin, is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is the major regulator of the adrenal cortex function. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological stress (along with its precursor corticotropin-releasing hormone from the hypothalamus). Its principal effects are increased production and release of corticosteroids. A deficiency of ACTH is a cause of secondary adrenal insufficiency and an excess of it is a cause of Cushing’s syndrome.
1.This product is composed of 39 amino acid residues, species differences only in the 25-33 position, 1-24 bits of the fragment with all the activity, twenty-fourth amino acid after the part only to maintain stability of the whole polypeptide structure. In the solution is highly - Helical structure. By partial hydrolysis of pepsin is still active.
2.This product is poor efficacy of oral invalid; intramuscular injection; intravenous injection effect is fast, but has a half-life of only 15min, hold time 1-3h.Adrenocorticotropic hormone, commonly referred to as ACTH and also known as corticotropin, is a polypeptide hormone produced in and secreted by the anterior pituitary gland. It is a key component in the hypothalamic-pituitary-adrenal axis, often produced in response to exogenous biological stress along with corticotropin-releasing hormone (which is also from the hypothalamus.) Its effects include increased production and release of corticosteroids and, as its name suggests, cortisol from the adrenal cortex.
3.ACTH acts through the stimulation of cell surface ACTH receptors, which are located primarily on adrenocortical cells of the adrenal cortex. This results in the synthesis and secretion of gluco- and mineralo-corticosteroids and androgenic steroids.
4.The ACTH receptor is a seven-membrane-spanning G protein-coupled receptor. Upon ligand binding, the receptor undergoes conformation changes that stimulate the enzyme adenylyl cyclase, which leads to an increase in intracellular cAMP and subsequent activation of protein kinase A. This ultimately results in stimulation of steroidogenesis. Steroidogenesis. Steroidogenesis is the biological process by which
steroids are generated from cholesterol and transformed into other steroids.
5.The pathways of steroidogenesis differ between different species, but the pathways of human steroidogenesis are shown in the figure. Products of steroidogenesis include: androgens testosterone estrogens and progesterone corticoids cortisol aldosterone ACTH acts at several key steps to influence the steroidogenic pathway in the adrenal cortex: ACTH stimulates lipoprotein uptake into cortical cells. This increases the bioavailability of cholesterol in the cells of the adrenal cortex. ACTH increases the transport of cholesterol into the mitochondria and activates its hydrolysis. ACTH Stimulates cholesterol side-chain cleavage enzyme, which makes the rate-limiting step in steroidogenesis. This results in the production of pregnenolone.
