Roles of prostaglandin E2-EP1 receptor signaling in regulation of gastric motor activity and emptying
Autor: | Takehito Satoh, Katsunori Saigenji, Sumito Mizuguchi, Katsuharu Arai, Youichiro Hattori, Izumi Hayashi, Takashi Ohno, Yukihiko Sugimoto, Takeo Saeki, Shuh Narumiya, Tsutomu Minamino, Masataka Majima, Takako Ae |
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Rok vydání: | 2010 |
Předmět: |
Male
medicine.medical_specialty Physiology Indomethacin In situ hybridization Dinoprostone Rats Sprague-Dawley Mice Physiology (medical) Internal medicine medicine Animals Receptors Prostaglandin E Cyclooxygenase Inhibitors Prostaglandin E2 Receptor In Situ Hybridization Mice Knockout Analysis of Variance Dose-Response Relationship Drug Hepatology Gastric emptying Reverse Transcriptase Polymerase Chain Reaction Chemistry Stomach Gastroenterology Muscle Smooth Rats Endocrinology medicine.anatomical_structure Gastric Emptying Eicosanoid Gastric Mucosa lipids (amino acids peptides and proteins) Signal transduction Homeostasis Signal Transduction medicine.drug |
Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 299:G1078-G1086 |
ISSN: | 1522-1547 0193-1857 |
DOI: | 10.1152/ajpgi.00524.2009 |
Popis: | It is widely accepted that the inhibition of gastric motor activity as well as the maintenance of gastric mucosal blood flow and mucous secretion are important for the homeostasis of the gastric mucosa. The present study was performed to ascertain whether or not endogenous PGs, which can protect the stomach from noxious stimuli, affect gastric motor activity and emptying. The myoelectrical activity of rat gastric smooth muscle was increased at intragastric pressures of over 2 cmH2O. Replacement of intragastric physiological saline with 1 M NaCl solution significantly increased PGI2and PGE2in stomach and suppressed the myoelectrical activity under a pressure of 2 cmH2O by 70%. Indomethacin inhibited the suppression of myoelectrical activity by 1 M NaCl. The myoelectrical activity under a pressure of 2 cmH2O was suppressed by continuous infusion of a selective EP1 agonist (ONO-DI-004, 3–100 nmol·kg−1·min−1) into the gastric artery in a dose-dependent manner, but not by that of the PGI receptor agonist beraprost sodium (100 nmol·kg−1·min−1). Suppression of myoelectrical activity with 1 M NaCl was inhibited by continuous infusion of a selective EP1 antagonist (ONO-8711, 100 nmol·kg−1·min−1) into the gastric artery. Furthermore, gastric emptying was tested in EP1 knockout mice and their wild-type counterparts. Gastric emptying was strongly suppressed with intragastric 1 M NaCl in wild-type mice, but this 1 M NaCl-induced suppression was not seen in EP1 knockout mice. These results suggest that PGE2-EP1 signaling has crucial roles in suppression of myoelectrical activity of gastric smooth muscles and inhibition of gastric emptying and that EP1 is an obvious target for drugs that control gastric emptying. |
Databáze: | OpenAIRE |
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