Ghrelin Ghrelin Ghrelin (pronounced ), the "hunger hormone", also known as lenomorelin (INN), is a peptide hormone produced by ghrelinergic cells in the gastrointestinal tract that functions as a neuropeptide in the central nervous system. Besides regulating appetite, ghrelin also plays a significant role in regulating the distribution and rate of use of energy. When the stomach is empty, ghrelin is secreted. When the stomach is stretched, secretion stops. It acts on hypothalamic brain cells both to increase hunger, and to increase gastric acid secretion and gastrointestinal motility to prepare the body for food intake. The receptor for ghrelin, the ghrelin/growth
Prolactin-releasing hormone Prolactin-releasing hormone Prolactin-releasing hormone, also known as PRLH, is a hypothetical human hormone or hormone releasing factor. Existence of this factor has been hypothesized as prolactin is the only currently known hormone for which almost exclusively negative regulating factors are known (such as dopamine, leukemia inhibitory factor, some prostaglandins) but few stimulating factors. While many prolactin stimulating and enhancing factors are well known (such as thyrotropin-releasing hormone, oxytocin, vasoactive intestinal peptide and estrogen) those have primary functions other than stimulating prolactin release and the search for hypothetical releasing factor or factors continues. The prolactin-releasing peptide identified in 1998 was a