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
Adrenocorticotropic hormone Adrenocorticotropic hormone Adrenocorticotropic hormone (ACTH, also adrenocorticotropin, corticotropin) is a polypeptide tropic hormone produced by and secreted by the anterior pituitary gland. It is also used as a medication and diagnostic agent. ACTH 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 cortisol by the cortex of the adrenal gland. ACTH is also related to the circadian rhythm in many organisms. Deficiency of ACTH is a sign of secondary adrenal insufficiency (suppressed production of