Which hormone is secreted from stomach that control intake of food:
D i.e. Ghrelin - Ghrelin, is released by stomachs, especially during fasting and stimulates appetites (orexigenic). - CCK, Peptide YY/PYY (secreted from entire gitract but especially from ileum & colon), glucagon like peptide (secreted by intestines d/t presence of food) and insulin (produced in response to GLP) are gastrointestinal hormonal factors, which suppress feeding i.e. cause satiety (anorexigenic). Whereas, ghrelin another gastrointestinal hormone produced mainly by stomach is orexigenic (i.e. increase appetite). - Growth hormone (GH) also k/a somatotropic hormone or somatotropin exes much of its effects through intermediate substances called somatomedins secreted by liver (and to a much less extent, other tissues). Because many effects of somatomedins on growth are similar to those of insulin, therefore somatomedins are also called insulin like growth factors (IGFs). Out of 4 somatomedins isolated, the most impoant is somatomedin C (or IGF-1) and pygmies of Africa & Levi-Lorain dwarf have congenital inability to synthesize significant amount of IGF-1. - Orexin (hypocretin) producing neurons occur in hypothalamus. Orexins A and B increase feeding (appetite) whereas, brains from humans with narcolepsy have fewer orexin producing neurons in hypothalamus. - Cholecystokinin (CCK) is secreted by I cells of upper small intestine (jejunum) and decreases feeding (antiorexigenic / aorexigenic), inhibits gastric emptying, and stimulates secretion of pancreatic juice rich in enzymes, contraction of gall bladder, secretion of glucagon & insulin and small intestine & colonic motality. It is a gastrointestinal hormone synthesized & released mainly by oxyntic cells of stomach (Guyton) / P or D1 cells of fundus of stomach. It is also produced by the intestine & epsilon cells of pancreas in small amounts. Ghrelin acts to stimulate hunger (appetite)Q. So blood levels rise during fasting, peak just before eating and then fall rapidly after a meal (orexigenic). In this way, it is counter pa of hormone leptin, produced by adipose tissue, which induces satiation (i.e. is anti-orexigenic) when present at higher levels. - Ghrelin is also produced in arcuate nucleus of hypothalamus and has marked growth hormone stimulating activity i.e. it stimulates GH secretion from anterior pituitary gland by acting directly on receptors in pituitary. - G protein coupled ghrelin receptor formerly k/a growth hormone secretagogue (GHS) receptor is expressed in arcuate nucleus, lateral hypothalamus, vagal afferent cell bodies & vagal afferent endings through out gastrointestinal tract. - It has an impoant role in neurotrophy, paicularly in hippocampus and is essential for cognitive adaptation to changing environment and process of learning.
Orexin
Insulin like growth hormone
Cholecystokinin
Ghrelin