Mechanisms of burn-induced impairment in gastric slow waves and emptying in rats.
Delayed gastric emptying is common following severe large cutaneous burns; however, the mechanisms of burn-induced delayed gastric emptying remain unknown. The aim of this study was to explore the possible involvement of hyperglycemia and cyclooxygenase-2 receptors in the burn-induced gastric dysrhythmias. Gastric slow waves and gastric emptying were assessed in rats 6 h following sham or burn injury. Animals were randomized to one sham-burn and seven burn groups: untreated; two groups of saline treated (control); insulin treated (5 IU/kg); cyclooxygenase-2 inhibitor treated (10 mg/kg); ghrelin treated (2 nmol/rat); and gastric electrical stimulation treated. It was found that 1) severe burn injury impaired gastric slow waves postprandially and delayed gastric emptying; 2) the impairment in gastric slow waves included a decrease in the slow-wave frequency and in the percentage of normal slow waves, and an increase in the percentage of bradygastria (P = 0.001, 0.01, and 0.01, respectively vs. preburn values). None of the gastric slow-wave parameters was significantly correlated with gastric emptying; 3) cyclooxygenase-2 inhibitor normalized burn-induced delayed gastric emptying (P = 0.3 vs. sham-burn), but not gastric dysrhythmias (P < 0.002 vs. sham), whereas insulin normalized both gastric emptying (P = 0.4 vs. sham-burn) and gastric dysrhythmias (P = 0.3 vs. sham-burn); 4) both gastric electrical stimulation and ghrelin accelerated burn-induced delayed gastric emptying (P = 0.002 and 0.04, respectively, vs. untreated burn). In conclusion, hyperglycemia alters gastric slow-wave activity and delayed gastric emptying, while cyclooxygenase-2 inhibition delays gastric emptying without altering gastric slow-wave activity.
Sallam
Hanaa S
HS
Department of Internal Medicine/Division of Gastroenterology, University of Texas Medical Branch, Galveston, Texas 77555-0655, USA.
Oliveira
Hermes M
HM
Liu
Suhuan
S
Chen
Jiande D Z
JD
D000818:Animals; D002056:Burns; D002210:Caprylates; D051546:Cyclooxygenase 2 / Q000494:pharmacology; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D005746:Gastric Emptying / Q000187:drug effects / Q000502:physiology*; D054439:Ghrelin; D008297:Male; D019518:Postprandial Period; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000502:physiology*; D013272:Stomach Diseases / Q000503:physiopathology
D002210:Caprylates; D052246:Cyclooxygenase 2 Inhibitors; D054439:Ghrelin; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; C031492:octanoic acid