Ghrelin 

A New Obesity Related Peptide

Ghrelin, an endogenous ligand for growth hormone seretagogue  receptor (GHS-Rs), regulates pituitary growth hormone (GH) secretion. GHS-Rs distributed on hypothalamic neurons and in the brainstem. Ghrelin participates in  energy balance in rodents by decreasing fat utilization without significantly changing energy expenditure or locomotor activity. Peripheral daily administration of Ghrelin caused weight gain by reducing fat utilization in mice and rats. Intracerebroventricular administration of Ghrelin generated a dose-dependent increase in food intake and body weight. Rat serum Ghrelin concentrations were increased by fasting and were reduced by re-feeding or oral glucose administration, but not by water ingestion. Ghrelin as a brain-gut peptide, in addition to its role in regulating GH secretion, enable to involve in regulation of food intake and body weight. A gut hormone designated as PYY (Peptide YY(3-36) (PYY(3-36)), a Y2R agonist) is one of the most potent orexigenic substances yet to be identified. PYY is released from the gastrointestinal tract postprandially in proportion to the calorie content of a meal. Information on PYY is found HERE

   Tschop M, et al. Nature, 407, 908~913 (2000)

   Hosoda, H, et al. J Biol Chem (2000 May 8)

   Kojima, M, et al. Nature 402,656-660 (1999)

   Wren A.M. et al, Endocrinology 141: 4325-4328, 2000

   More references of Ghrelin

A new gut peptide, is specifically expressed in enteroendocrine cells of the stomach. 1). The amino acid sequence of human Prepro- Motilin- Related Peptide/ m46 protein is completely identical with human prepro-Ghrelin  except Ser²⁶ is not octanoylated. 2). The amino acid sequence of rat Pro-Motilin-Related Peptide/m46 Protein is also completely identical with rat Pro-Ghrelin except Ser²⁶ is not octanoylated. 3). Human Motilin-Related Peptide/m46 Protein (24-41) is identical with human Des- octanoyl³- Ghrelin(1-18). 4). Rat and mouse Motilin-Related Peptide/m46 Protein (24-41) is also identical with rat Des-octanoyl³-Ghrelin

Tomasetto C., et al. Gasenterology 119, 395-405 (2000)

Kojima, M, et al. Nature 402,656-660 (1999)

Review by Dr, Jaw-Kang Chang

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Intravenous injection of Ghrelin (Rat), Ghrelin (Human) stimulates growth hormone release

Anti-Ghrelin (Rat) Antibody (H-031-31) works on IHC mapping (1:70)

Normal plasma level of human Ghrelin = 87.79±10.27 pg/ml (Mean ± SE, n=7)*

Normal plasma level of Rat Ghrelin =      74.87 ± 8.22 pg/ml (Mean ± SE, n=10)*

Dr. C Y  Bowers, School of Medicine, Tulane University Medical Center

* Plasma was extracted using C18 column