Ghrelin growth hormone secretagogue receptor, with the "GHS-R1b" splice being inactive) is involved in mediating a wide variety of biological effects of ghrelin, including: stimulation of growth hormone release, increase in hunger, modulation of glucose and lipid metabolism, regulation of gastrointestinal motility and secretion, protection of neuronal and cardiovascular cells, and regulation of immune function. They are present in high density in the hypothalamus and pituitary, on the vagus nerve (on both afferent cell bodies and afferent nerve endings) and throughout the gastrointestinal tract. Ghrelin promotes intestinal cell proliferation and inhibits apoptosis during inflammatory states and oxidative stress. It also suppresses
Melanocyte-stimulating hormone Melanocyte-stimulating hormone The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the pars intermedia of the anterior lobe of the pituitary gland. Synthetic analogues of α-MSH, such as afamelanotide (melanotan I; Scenesse), melanotan II, and bremelanotide (PT-141), have been developed and researched. The various forms of MSH are generated from different cleavages of the proopiomelanocortin protein, which also yields other important neuropeptides like adrenocorticotropic hormone. Melanocytes in skin make and