nounIntermediate
Definition
28-amino-acid peptide hormone secreted primarily by X/A-like cells in the stomach fundus.

Detailed Explanation

28-amino-acid peptide hormone secreted primarily by X/A-like cells in the stomach fundus. Called the 'hunger hormone,' ghrelin is the only known circulating peptide that stimulates appetite. Levels rise before meals and fall after eating. Ghrelin also stimulates growth hormone release from the pituitary (via GHS-R1a receptor), regulates glucose homeostasis, and modulates reward and stress pathways. Uniquely, ghrelin requires octanoylation (a fatty acid modification on Ser3) by the enzyme GOAT for receptor activation.

Key Facts

  • 28-amino-acid peptide hormone secreted primarily by X/A-like cells in the stomach fundus.
  • Called the 'hunger hormone,' ghrelin is the only known circulating peptide that stimulates appetite.
  • Levels rise before meals and fall after eating.
  • Ghrelin also stimulates growth hormone release from the pituitary (via GHS-R1a receptor), regulates glucose homeostasis, and modulates reward and stress pathways.
  • Uniquely, ghrelin requires octanoylation (a fatty acid modification on Ser3) by the enzyme GOAT for receptor activation.
Related Terms Leptin GLP-1 Incretin Hormone Acylation

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