Ghrelin

links: Hormones reference: 4-18-2021

Ghrelin #

Produced by the GI tract.

• Stimulates hunger and secretion of stomach acid and motility, it is released when fasting.
• Decreases during sleep, but nevertheless is important. Sleep deprivation lowers leptin and increases ghrelin.
  • Stimulates Growth Hormone during sleep.
    • Levels rise between 1:00 - 3:00AM
• Increases Aldosterone and Cortisol.
• It becomes active when Caprylic Acid is attached poststranslationally to some serine via ghrelin O-acyltransferase. Other side chains are possible, like significant amounts of C10-ghrelin being seen in mice.
• A ghrelin–growth hormone axis drives stress-induced vulnerability to enhanced fear
  • Systemic/Intra-amygdala infusion of a ghrelin receptor agonist produced an enhancement of fear memory but did not increase CRH/corticosterone.
    • Ghrelin receptor antagonism during repeated stress abolished stress-related enhancement of fear memory without blunting the stress-induced Corticosterone release.