title: The effects of 5-hydroxytryptamine1a receptor agonist, buspirone on the gastric fundus accommodation in an animal model using guinea pigs.
abstract: BACKGROUND
  To date, few animal experiments have been conducted to examine the effects and mechanisms of buspirone in inducing the relaxation of the gastric fundus. The aim of this study is to examine the effects and mechanisms of buspirone, 5-HT(1a) receptor agonist, in the accommodation of gastric fundus muscle in an animal experimental model using guinea pigs.
  
  
  METHODS
  In the current study, we performed an immunohistochemistry for 5-HT(1a) receptors in the tissue samples collected from the stomach of guinea pig, an ex vivo experiment to examine the electrical field stimulation (EFS)-induced relaxation of the circular muscle in the gastric fundus in guinea pigs and an in vivo experiment to measure the intragastric pressure through the insertion of the balloon catheter in the fundus.
  
  
  RESULTS
  Immunohistochemical stains for 5-HT(1a) receptor could confirm the expression of 5-HT(1a) receptor in guinea pig stomach. There was a significant dose-dependent inhibition of the EFS-induced relaxation of fundic muscle strips following the treatment with WAY-100635 (5-HT(1a) antagonist), but this was significantly improved following the treatment with buspirone. An in vivo measurement of the gastric fundic tone showed that there was a significant decrease in the intragastric pressure at same volume by pretreatment with buspirone as compared with the vehicle control, but this could be prevented with the treatment with WAY-100635.
  
  
  CONCLUSIONS
  Based on our results, it can be concluded that buspirone is effective in relaxing the gastric fundus via 5-HT(1a) receptor pathway in both in vitro and in vivo experimental models using guinea pigs.
authors: Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors: Y H
authors: YH
authors: Youn
authors: E J
authors: EJ
authors: Choi
authors: Y H
authors: YH
authors: Lee
authors: T
authors: T
authors: Oshima
authors: H
authors: H
authors: Miwa
authors: H
authors: H
authors: Park
mesh_terms: D000818:Animals; D002065:Buspirone / Q000494:pharmacology*; D004558:Electric Stimulation; D005260:Female; D005748:Gastric Fundus / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D006168:Guinea Pigs; D008297:Male; D009130:Muscle, Smooth / Q000502:physiology; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism / Q000502:physiology*; D058825:Serotonin 5-HT1 Receptor Agonists / Q000494:pharmacology*; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000494:pharmacology
chemical_list: D058825:Serotonin 5-HT1 Receptor Agonists; D058829:Serotonin 5-HT1 Receptor Antagonists; D044282:Receptor, Serotonin, 5-HT1A; D002065:Buspirone
keywords: 5-HT1a receptor; buspirone; gastric fundic accommodation; guinea pig