THE GHRELIN PENTAPEPTIDE INHIBITS THE SECRETION

Department of Physiological Sciences, Faculty of Veterinary Medicine, Warsaw Agricultural University, Warsaw, PolandGhrelin, a 28 amino acids polypeptide was recognized as an endogenous ligand forthe growth hormone secretagogue receptor. It turned out that the entire sequence ofghrelin is not necessary for performing the above-mentioned functions. It wassuggested that 5 residues (Gly-Ser-Ser(n-octanoyl)-Phe, pentaghrelin) constitutedfunctionally active part of the full-length polypeptide. Ghrelin-28 was found toinhibit pancreatic enzyme output in rats, though the effect of pentaghrelin was notstudied so far. The study aimed to determine the involvement of pentaghrelin inpancreatic juice secretion in anaesthetized rats. Male Wistar rats (220 – 20 g bodyweight, b. wt.) were anesthetized, the external jugular vein and common biliary-pancreatic duct were cannulated. Pentaghrelin boluses (iv, 1.2, 12, and 50 nmol kg