noun, plural: lipotropins
Lipotropin is a polypeptide hormone secreted by the anterior pituitary, particularly by the corticotrophic cell. Corticotrophic cells are one of the different types of cells in the anterior pituitary. Apart from the lipotropin, they also produce and release melanocyte-stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH).
Lipotropin is a large polypeptide (about 90 amino acid units) produced through the cleavage of proopiomelanocortin protein (i.e. POMC, which also serves as a precursor to other neuropeptides like adrenocorticotropin).
The main physiological role of lipotropin is believed to be associated with promoting fat mobilization from adipose tissues. It appears to regulate the excess amounts of fats in adipose tissues and liver. It has an affinity for lipids, improving the utilization of fats in the body, thus, preventing the accumulation of fats in tissues. The condition in which there is an excess of fats in tissue or bodily organ is referred to as lipotrophy.
Lipotropin is also associated with skin darkening. It was reported to stimulate melanocytes to produce melanin (dark pigment). It also acts as a precursor to certain endogenous opiates, such as endorphins.
Word origin: lipotrop(ic) + -in
- lipid-mobilizing hormone
- lipotropic hormone
- lipotropic pituitary hormone
- lipotropic (adjective, of, relating to lipotropin; having the affinity for lipids to promote mobilization of fats thus preventing accumulation of fats in tissues and organs)