W27-L8: Role of GI system in obesity Flashcards
How is food intake regulated?
two classes of neurones in arcuate nucleus, NPY + AGRP (stimulate eating) and POMC neurones which creates aMSH (inhibit eating)
What regulates the hypothalamus with regards to food intake?
hormones from the gut and fat
Where is ghrelin mainly synthesised?
Stomach
What is the result of a stepped increase with ghrelin concentration?
stepped increase in food intake
How does ghrelin work by NPY and how do we know this?
ghrelin works by increasing the release of NPY, antagonism of NPY receptor diminishes effect of ghrelin on food intake so therefore ghrelin works via NPY
What hormone does ghrelin oppose?
Leptin
How does CCK’s anorectic actions mainly occur?
Via CCK 1 R on the vagus nerve
Why is the role of PYY?
Reduces food intake
What is Oxyntomodulin?
A product of the glucagon gene released in response to food
What is the role of Oxyntomodulin?
Reduces food intake
Are Oxyntomodulin and PYY additive in their effects on food intake?
Yes, together decrease it more than one alone
What is GIP?
Gastric inhibitory peptide
How does GIP work?
promotes triglyceride clearance from the circulation by activating lipoprotein lipase
What is the effect of Glucagon like protein 1?
promotes satiety and reduces food intake
Do gut hormones have an important role in the defence of body weight?
Yes, their respective levels change to oppose weight change, even a year after weight loss
