title: Acute peripheral metabolic effects of intraarterial ghrelin infusion in healthy young men.
abstract: BACKGROUND
  Ghrelin is the endogenous agonist for the growth hormone secretagogue receptor (GHS-R). Intravenous administration of ghrelin induces insulin resistance and hyperglycemia and increases the levels of free fatty acids (FFA).
  
  
  OBJECTIVE
  To investigate whether these effects are mediated directly by ghrelin in skeletal muscle tissue.
  
  
  METHODS
  This study was single blinded, randomized, and placebo controlled. Eight healthy men (25.5 ± 3.1 years) received 240 min of intraarterial ghrelin infusion (4.2 ng × kg(-1) × min(-1)) into one femoral artery and intraarterial placebo infusion into the contralateral artery. Simultaneous blood samples were drawn from both femoral veins and muscle biopsies were obtained from both legs during both a basal period and during a hyperinsulinemic and euglycemic clamp period.
  
  
  RESULTS
  Ghrelin significantly elevated venous FFA levels and venous dilution of palmitate, suggestive of increased lipolysis. Glucose metabolism was unchanged, and there were no direct effects on pertinent enzymes in the insulin signaling cascade. The metabolic clearance rate of acyl ghrelin was 12.5 ± 3.3 ml × kg(-1) × min(-1). Acyl and desacyl ghrelin levels both increased.
  
  
  CONCLUSIONS
  The results of this study suggest that ghrelin may stimulate lipolysis directly in skeletal muscle.
authors.affiliation: Department of Pediatrics, Aarhus University Hospital Skejby, Dk-8200 Aarhus N, Denmark. etv@dadlnet.dk
authors.forename: Esben Thyssen
authors.initials: ET
authors.lastname: Vestergaard
authors.forename: Mads
authors.initials: M
authors.lastname: Buhl
authors.forename: Jakob
authors.initials: J
authors.lastname: Gjedsted
authors.forename: Michael
authors.initials: M
authors.lastname: Madsen
authors.forename: Niels
authors.initials: N
authors.lastname: Jessen
authors.forename: Soren
authors.initials: S
authors.lastname: Nielsen
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Gaylinn
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liu
authors.forename: Michael O
authors.initials: MO
authors.lastname: Thorner
authors.forename: Niels
authors.initials: N
authors.lastname: Moller
authors.forename: Jens Otto Lunde
authors.initials: JO
authors.lastname: Jorgensen
mesh_terms: D000328:Adult; D004396:Coloring Agents; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D005263:Femoral Artery; D054439:Ghrelin / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D015309:Glucose Clamp Technique; D006801:Humans; D007208:Indocyanine Green; D007261:Infusions, Intra-Arterial; D007328:Insulin / Q000502:physiology; D007773:Lactates / Q000097:blood; D007866:Leg / Q000098:blood supply; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D008660:Metabolism / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism; D010168:Palmitates / Q000097:blood / Q000378:metabolism; D012039:Regional Blood Flow / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects; D016037:Single-Blind Method; D055815:Young Adult
chemical_list: D004396:Coloring Agents; D005230:Fatty Acids, Nonesterified; D054439:Ghrelin; D007328:Insulin; D007773:Lactates; D010168:Palmitates; C422650:ghrelin, des-n-octanoyl; D007208:Indocyanine Green; D005947:Glucose