Clinical Significance: Ghrelin is a novel 28 amino acid peptide derived by post-translational processes from a preproghrelin consisting of 117 residues, secreted by the stomach with specific receptors in the brain involved in appetite regulation. It conveys information to the brain thereby increasing appetite, food intake and body weight and influences the release of growth hormone. Ghrelin is a growth hormone-releasing peptide which acts as an endogenous ligand of the growth hormone secretagogue receptors (GHS-Rs). Ghrelin levels are inversely correlated with body weight and are higher during weight loss.
Ghrelin is measured by EIA/ELISA.
Patient should be fasting for 10 – 12 hours prior to collection of specimen. Patient should not be on any medications or supplements that may influence: Cholecystokinin (CCK), Glucose, Growth Hormone, Insulin and/or Somatostatin levels, if possible, for at least 48 hours prior to collection.
Collect 10mL blood in special ISI GI Preservative tube yielding special GI plasma and separate in refrigerated centrifuge as soon as possible. Transfer 3-5mL immediately into non-glass shipping vial. Minimum specimen size is 1mL. Freeze specimen at -20°C. Variance from these instructions must be disclosed to ISI prior to specimen analysis.
Ship specimens frozen in dry ice.
1. T Shiiya, M Nakazato, M Mizuta, Y Date, MS Mondal, M Tanaka, S Nozoe, H Hosoda, K Kangawa, S Matsukura. Plasma Ghrelin Levels in Lean and Obese Humans and the Effect of Glucose on Ghrelin Secretion. J Clin Endo Metab 2002; 87(1): 240-244.
2. DE Cumings, DS Weigle, RS Frayo, PA Breen, MK Ma, EP Dellinger, JQ Purnell. Plasma Ghrelin Levels After Diet-Induced Weight Loss or Gastric Bypass Surgery. N Engl J Med 2002; 346 (21): 1623-1630.