Gut hormones and appetite

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Created by
Hayley

Cards (4)

  • What is Roux-en-Y gastric bypass and what are its effects?
    Dissect most of the stomach away from the rest and add to distal small intestine, leave a part of the stomach the size of an egg
    Exaggerated GLP1 release in response to food, increased insulin secretion
    Metabolic U-turn in diabetic patients, restores insulin sensitivity within 48 hours post-surgery
    Weight loss with time, can keep off for 10+ years
    Change in eating behaviour - loss drive to over-eat, sweet-food cravings, stop obsessing about food - increase D2 receptor availability
    Can lead to osteoporosis and alcohol dependence
  • Describe overview of hunger/satiety circuits in arcuate nucleus
    NPY neurons project from the arcuate nucleus to the PVN to drive feelings of hunger (driven by grehlin), and POMC/CART neurons project from the arcuate nucleus to the PVN to drive feelings of satiety (do this via alpha-MSH, which binds to MC4Rs)
    Also inhibitory GABA projections from hunger to satiety circuit
    NPY antagonises MC4Rs to downregulate metabolism
    Leptin receptors VTA for rewarding effect of food (can be affected by RYGB, resets, rescues blunted mesolimbic pathways) - complex signal transduction pathways
  • Gut-brain connection for nutrient sensing?
    Neuropod cells synapse with sensory neurons small intestine, so uninterrupted circuit between gut and brain
    Rabies infection EEC rabG expressing mice (used to show functional connections) showed infection spread up vagus nerve to nodose ganglion and NTS
    Used to signal sugar stimuli to the brain - have sweet taste receptors and sodium-glucose transporters, and optogenetic silencing of cells stops vagal response to sugars
    Duodenal neuropod cells discern sugar via Glu signalling, and sweetener via purinergic signalling
  • Role of enteroendocrine cells
    EEC cells drive food aversion and reward
    Paper where CNO administration to DREADD associated EECs after a sucrose meal, lead to mice avoiding previously preferred sucrose
    Preference is CCK and GLP1 driven