Effect of ghrelin on small intestinal transit and interdigestive gastrointestinal migrating myoelectric complex in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of ghrelin on small intestinal transit and intergigestive gastrointestinal migrating myoelectric complex (MMC) in rats.</p><p><b>METHODS</b>After a 24-hour fasting, the rats with or without pretreatment with receptor antagonist (D-Lys3)GHRP-6 were given intravenous injections of ghrelin at different doses to observe the changes in small intestinal transit. The MMCs of the fasting rats were recorded using a multilead physiological recording system, and their changes observed in response to intravenous ghrelin injections, or to ghrelin injection following pretreatment with atropine, phentolamine, propranolol, L-arginine or (D-Lys3)GHRP-6, respectively.</p><p><b>RESULTS</b>Ghrelin enhanced the small intestinal transit dose-dependently, and this effect was inhibited by application of ghrelin receptor antagonist. Ghrelin also showed excitatory effect on the MMCs, which was inhibited by atropine, L-arginine or (D-Lys3)GHRP-6, but not by propranolol and phentolamine.</p><p><b>CONCLUSION</b>Ghrelin can promote gastrointestinal motilities, and its excitatory effects rely on the cholinergic pathway in close relation to nitric oxide pathway. Ghrelin receptor is involved in its action in promoting the gastrointestinal motilities.</p>

Effect of ghrelin on duodenal myoelectric activity in conscious rats / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of ghrelin on the duodenal myoelectrical activity during the feeding state and the fasting state in rats.@*METHODS@#One pair of bipolar silver electrodes were chronically implanted in the duodenal serosa of rats for electromyography. The myoelectrical activity was recorded when ghrelin was injected intravenously into rats during the feeding state or the fasting state. Some rats were pretreated with atropine, phentolamine, propranolol, L-arginine, and (D-Lys3)GHRP-6 respectively to explore the mechanism of ghrelin.@*RESULTS@#Duodenal migrating myoelectrical complex (MMC) could be induced by ghrelin in the feeding state. Ghrelin could shorten the length of duodenal MMC cycle and increase the amplitude and frequency of phase III during the fasting state. The percentage of phase III in the MMC cycle did not change. These effects were inhibited by atropine and L-arginine (D-Lys3)GHRP-6, but not by propranolol and phentolamine.@*CONCLUSION@#Ghrelin seems to be closely related to the duodenal motility. The excitatory effect of ghrelin on duodenal MMC might rely on the cholinergic pathway, and have a close relationship with NO. The receptor of ghrelin can regulate its activity.