1. In the name of God

2. Gut Hormones in the control of appetite
Ali Haghzaheri

4. Introduction Obesity is one of the greatest threats to the health
it is essential to understand the physiology of appetite control
Obesity is a risk factor of type2 diabetes mellitus , CVD , certain forms of cancer
Obesity increases mortality
Weight loss can reduce the morbidity & mortality
Obesity is defined as BMI of 30 or more
Exp Physiol 89.5 p 507 – “Gut hormones ih the control of appetite” , K.G Murphy & S.R. Bloom

5. Central mechanisms
Hypothalamus is key CNS region involved in appetite regulation
ARC play a crucial role in receiving & integrating signals
ARC involved are 2 types : POMC & NPY\POMC
POMC is precursor molecule that gives rise to the anorectic peptide alpha-MSH
AgRP increases food intake
NPY is a potent orexigenic agent & stimulates feeding
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

6. Adipostat factors Leptin
Is expressed & secreted by adipocytes in white adipose tissue
Circulates in plasma at concentration proportional to fat mass
Provides the hypothalamus with information on the extent of body fat stores
Reduces food intake & body weight
Increases energy expenditure
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

7. Adipostat factors Insulin
Is not released from adipocytes themselves, basal circulating levels correlated with body adiposity level
Reduces food intake & body weight
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

8. Gut Hormones Leptin & insulin can not explain appetite changes
Endocrine & neural signals from gut are more responsible
Stomach distension is more important than content in the neural suppression of food intake
Nutrient content plays a larger role in small intestine , stimulating satiety
Gut hormones play a important physiological role in satiety
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

9. CCK First gut hormone implicated in the control of appetite .
Presence of digestive products in the intestinal lumen stimulates the release of CCK from proximal small intestine
Has Anorectic effects
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

10. Ghrelin
Only peripherally active appetite-stimulating hormone so far discovered.
Potently stimulates food intake & GH secretion
Major source is stomach
Is orexigenic
Increases during fasting & fall rapidly after a meal
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

11. PP It is found predominantly in the endocrine pancreas.
Its release is stimulated by food intake.
Postprandial plasma levels are proportional to caloric intake .
Though other factors, including gastric distension , vagal tone , blood glucose levels and GI hormones also influence its release.
PP inhibits pancreatic exocrine secretion & gallbladder contraction & GI motility.
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

12. PYY
PYY is produced by gut endocrine cells & is raleased into the circulation postprandially .
PYY increases fluid & electrolyte absorption from the ileum
& inhibits gut motility , meal-induced pancreatic & gastric secretion & gallbladder & gastric emptying.
It also acts as a vasocanstrictor.
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

13. GLP-1
GLP-1 is produced by posttranslational processing of preproglucagon gene in the CNS & the intestine & colon.
GLP-1 is released into circulation in response to nutrient intake
It appear to function as satiety signals.
Physiological actions of GLP-1: stimulation of insulin release,suppression of gastric acid secretion & slowing gastric emtying.
GLP-1 receptors are found in the brainstem,ARC & PVN , in addition to various peripheral tissues.
Exp Physiol 89.5 pp , K.G Murphy & S.R. Bloom

14. Orexigenic neuropeptides
NPY
AgRP
MCH (melanin-concentrating hormones)
Galanin
Ghrelin
GHRH (Growth hormone Releasing hormone)
Orexin
Norepinephrine
Beta-Endorphin
Molecular interventions ,volume2 ,issue8 , December 2002 ,p 497

15. Anorexigenic neuropeptides
Alpha-MSH
Corticopin-releasing hormone
CCK
Somatostatin
Thyrotropin-releasing hormone
Calcitonin-gene-related peptide
GLP-1
GLP-2
Serotonin
Oxytocin
Molecular interventions ,volume2 ,issue8 , December 2002 ,p 497

16. Exp Physiol 89.5 (2004),p 508

17. The FASEB journal , vol 18 , p 442 , March 2004

18. Molecular interventions,volume2,issue8,December2002,p 497

19. References
Exp Physiol 89.5 (2004) pp – “Gut hormones ih the control of appetite” , K.G Murphy & S.R. Bloom
Endocrinology,147 (6),March 2006,pp : “Direct Stimulation of Ghrelin Secretion by Sympathetic Nerves” Thomas O. Mundinger ,…
Molecular interventions ,volume2 ,issue8 , December 2002 ,pp : “Ghrelin & the regulation of food intake & Energy Balance” Hiroshi Hosoda ,…

20. The FASEB journal , vol 18 , pp , March 2004 : “Ghrelin,appetite,and gastric motility: the emerging role of the stomach as an endocrine organ” AKIO INUI,…