obesity Flashcards
what is leptin
body fat sensor expressed in fat cells that reduces food intake
2 groups of neurons affected by leptin
neuropeptide and agouti-related peptide, pro-opiomelanocortin and alpha-melanocyte stimulating hormone
role of neuropeptide and agouti-related peptide
reduce leptin to encourage eating and reduced expenditure
role of pro-opiomelanocortin and alpha-melanocyte-stimulating hormone
increase leptin levels to decrease food intake and increase energy expenditure
leptin resistance
high levels caused by synthesis or target defects
obesity and genetics
30-40% inheritability, approx 200 single gene disorders that are not leptin or leptin receptor
fatty acid absorption
solubilised to micelles and hydrolysed by lipase for free fatty acids to be absorbed by intestine
lifestyle treatments for obesity
dieting - eat less, eat but do not digest, eat and burn off
drug targets
appetite suppression, decreased absorption, increased metabolism
hunger signals
ghrelin - by meal and progesterone - days
satiety signals
amylin - by meals and leptin by days
melanocortin pathway
stimulated by obesity - serotonin binds to 5htc in pituitary stimulating pro-opiomelanocortin, cleaved to alpha-melanocyte which exerts its effect
lorcaserin
5ht2c receptor agonist, BMI>30, causes headaches, infections, depression - withdrawn
rimonabant
cannabinoid receptor ligand, psychiatric side effects so withdrawn
lipstatin
forms stable intermediate with lipase (decreases absorption) easily oxidised
