title: Insulin regulates plasma ghrelin concentration.
abstract: Ghrelin is a novel gastric peptide which stimulates growth hormone and has orexigenic and adipogenic properties. Plasma ghrelin is influenced by nutritional status and is thought to play a role in regulating food intake and body weight. We examined the effect of infusing insulin (40 mU/m(2)/min) for 2 hours while maintaining euglycemia on plasma ghrelin in 8 subjects (5 M, 3 F) aged 46 +/- 4 yrs (mean +/- SEM). Plasma insulin increased from 78 +/- 9 to 564 +/- 23 pmol/L during and returned rapidly to basal values after stopping the insulin infusion. Plasma ghrelin decreased from 85 +/- 28 to 61 +/- 18 pmol/L (p < 0.01) by 90 minutes of and continued to be suppressed for 15 minutes after the insulin infusion was discontinued. Subsequently, plasma ghrelin rose rapidly to near-basal values (81 +/- 23 pmol/L) within 60 minutes. The reciprocal relation between insulin and ghrelin was observed consistently in all subjects with the maximum insulin-induced suppression of ghrelin ranging from 19 to 64% (mean 32 +/- 5) and occurring 90-135 minutes after starting the insulin infusion (median 120). These findings indicate that insulin is a physiological and dynamic modulator of plasma ghrelin and that insulinemia possibly mediates the effect of nutritional status on its concentration.
authors.affiliation: Division of Clinical Epidemiology and Preventive Medicine, UCLA School of Medicine, Los Angeles, California 90024, USA. msaad@mednet.ucla.edu
authors.forename: Mohammed F
authors.initials: MF
authors.lastname: Saad
authors.forename: Basem
authors.initials: B
authors.lastname: Bernaba
authors.forename: Chii-Min
authors.initials: CM
authors.lastname: Hwu
authors.forename: Sujata
authors.initials: S
authors.lastname: Jinagouda
authors.forename: Salwa
authors.initials: S
authors.lastname: Fahmi
authors.forename: Ella
authors.initials: E
authors.lastname: Kogosov
authors.forename: Rima
authors.initials: R
authors.lastname: Boyadjian
mesh_terms: D000328:Adult; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D005260:Female; D054439:Ghrelin; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000097:blood; D007328:Insulin / Q000008:administration & dosage* / Q000097:blood; D008297:Male; D008875:Middle Aged; D036361:Peptide Hormones; D010455:Peptides / Q000097:blood*
chemical_list: D054439:Ghrelin; D007004:Hypoglycemic Agents; D007328:Insulin; D036361:Peptide Hormones; D010455:Peptides