Ghrelin improves burn-induced delayed gastrointestinal transit in rats

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2007-01, Vol.292 (1), p.R253-R257
• Main Authors: Sallam, H. S, Oliveira, H. M, Gan, H. T, Herndon, D. N, Chen, J. D. Z
• Format: Article
• Language: English
• Subjects: Animals; Atropine - pharmacology; Burns; Burns - physiopathology; Colon - drug effects; Colon - physiology; Coloring Agents; Digestive system; Gastric Emptying - drug effects; Gastric Emptying - physiology; Gastrointestinal Transit - drug effects; Gastrointestinal Transit - physiology; Ghrelin; Intestines - drug effects; Intestines - physiology; Male; Muscarinic Antagonists - pharmacology; Peptide Hormones - pharmacology; Peptides; Phenolsulfonphthalein; Rats; Rats, Sprague-Dawley; Rodents; Stimulation, Chemical
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.00100.2006

1 Division of Gastroenterology, Departments of Internal Medicine and Surgery, 2 Shriners Hospital for Children, University of Texas Medical Branch, Galveston, Texas Submitted 7 February 2006 ; accepted in final form 2 September 2006 Delayed gastrointestinal transit is common in patients with severe burn. Ghrelin is a potent prokinetic peptide. We aimed at testing the effect of ghrelin on burn-induced delayed gastrointestinal transit in rats. Gastric emptying (GE), intestinal transit (IT), and colonic transit (CT) studies were performed in male Sprague-Dawley rats. Rats were randomized into two main groups as follows: sham injury and ghrelin-treated burn injury with doses of 0, 2, 5, and 10 nmol/rat ip 6 h after burn. Sham/burn injury was induced under anesthesia. Rats received a phenol red meal 20 min following ghrelin injection. Based on the most effective ghrelin dose, 1 mg/kg sc atropine was given 30 min before the ghrelin in one group of rats for each study. The rats in each group were killed 30–90 min later; their stomachs, intestines, and colons were harvested immediately, and the amount of phenol red recovered was measured. Percentage of gastric emptying (GE%) and geometric center for IT and CT were calculated. We found 1 ) severe cutaneous burn injury significantly delayed GE, IT, and CT compared with sham injury ( P < 0.05); 2 ) ghrelin normalized both GE and IT, but not the CT; 3 ) the most effective dose of ghrelin was 2 nmol/rat; and 4 ) atropine blocked the prokinetic effects of ghrelin on GE% and IT. In conclusion, ghrelin normalizes burn-induced delayed GE and IT but has no effect on CT in rats. The prokinetic effects of ghrelin are exerted via the cholinergic pathway. Ghrelin may have a therapeutic potential for burn patients with delayed upper gastrointestinal transit. ghrelin; burn; gastric emptying; intestinal transit; colon transit Address for reprint requests and other correspondence: J. Chen, 1108 the Strand, Rm. 221, Univ. of Texas Medical Branch, Galveston, TX 77555-0632 (e-mail: jianchen{at}utmb.edu )