l7 -ghrelin
- Created by: BKW
- Created on: 09-01-20 14:31
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- L7 - Ghrelin
- What is it?
- Growth Hormone releasing peptide secreted by the gut
- Plays a role in energy homeostasis
- In rodents Ghrelin stimulates feeding and weight gain
- Plasma ghrelin concentrations ^^^ during fasting and vvv soon after eating
- Mediates it's effects by stimulating hypothalamic orexigenic neurones that enhance feeding eg NPY
- In rodents it appears to act as peripheral hunger signal to promote appetite and fat growth
- Faulconbridge et al injected ghrelin into rodents - ghrelin ^^^ food intake, time between injection and first meal vvv, ^^^ in average size of first meal
- Ghrelin and humans
- Ghrelin levels rise progressively between meals and fall after feeding
- they track and induce hunger
- Wren et al - study on 9 healthy pps IV ghrelin or saline - found Ghrelin ^^^ food intake and enhanced visual alalogue scores of hunger - shows it a potent hunger signal
- pps know they get a meal so ghrelin rises knowing they get food
- Cummings et al 6 male pps Measured ghrelin levels before spontaneously initiated meals - found pre meal ^^^ in ghrelin and hunger scores and ghrelin similar. - ghrelin plays role in meal initiation
- Arosio et al - 6 healthy pps examined the effect of cephalic phase on ghrelin response to feeding found vvv in ghrelin after sham and real feed and n diff in patterns of response
- the cephalic response to nutrient intake plays a role in the control of ghrelin secretion
- cephalic phase = gastric secreton before food enters stomach
- the cephalic response to nutrient intake plays a role in the control of ghrelin secretion
- Ghrelin levels rise progressively between meals and fall after feeding
- Ghrelin & obesity
- plasma ghrelin concentrations are ^^^ in anorexia &vvv in obesity
- Ghrelin levels fall after gastric bypass surgery
- Plasma ghrelin concentrations are increased after weight loss induced by dieting
- Plasma ghrelin levels are ^^^ in patients with Pradi Willi syndrome
- Obese individuals fail to supress ghrelin secretion post-meal
- English et al 13lean 10obese pps - looked at effects of test meal on plasma ghrelin concentrations
- found fasting ghrelin ^^^ in lean subjects, plasma ghrelin vvv by 40%in lean subjects after meal but n change in circulating ghrelin in obese group
- lack of ghrelin suppression in obese could = ^^^ food intake and be involved in obesity
- found fasting ghrelin ^^^ in lean subjects, plasma ghrelin vvv by 40%in lean subjects after meal but n change in circulating ghrelin in obese group
- English et al 13lean 10obese pps - looked at effects of test meal on plasma ghrelin concentrations
- What is it?
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