title: Olanzapine May Inhibit Colonic Motility Associated with the 5-HT Receptor and Myosin Light Chain Kinase.
abstract: OBJECTIVE
  To study whether the effects of olanzapine on gastrointestinal motility is related to the serotonin antagonism and myosin light chain kinase.
  
  
  METHODS
  Male Sprague-Dawley rats were randomly divided into four groups. Olanzapine gavage was performed for each treatment group during the course of 30 continuous days, while the same volume of saline was given to the rats in the control group. Defecation of the rats was observed on days 7 and 30 after olanzapine gavage. The effects of olanzapine on contraction of colonic smooth muscles were observed in ex vivo experiments. A Western blot was used to evaluate expression levels of the serotonin transporter (SERT) and MLCK in colon segments of the rats.
  
  
  RESULTS
  ResultsaaCompared to the control group, 5-160 µ M of olanzapine could inhibit dose-dependently the contraction of colonic smooth muscle ex vivo experiments. The maximum smooth muscle contraction effects of 5-HT and acetylcholine significantly decreased after treatment with 40-160 µ M of olanzapine. Constipation was found in the olanzapine-treated rats on day 7 and have sustained day 30 after gavage. Expression of MLCK in olanzapine-treated rats was significantly decreased, whereas the expression of SERT significantly increased on the day 7, then significantly decreased on the day 30 after olanzapine gavage.
  
  
  CONCLUSIONS
  SERT and MLCK may involve in the inhibition of colonic contraction induced by olanzapine.
authors.affiliation: Tianjin Mental Health Center, Tianjin, China.
authors.forename: Jiarui
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Qiao
authors.affiliation: Department of Integrated Traditional Chinese Medicine and Western Medicine, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Le
authors.affiliation: Tianjin Mental Health Center, Tianjin, China.
authors.forename: Daliang
authors.initials: D
authors.lastname: Sun
authors.affiliation: Department of Neurology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yangtai
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Department of Neurology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Zezhi
authors.initials: Z
authors.lastname: Li
keywords: Antipsychotic agents; Intestinal motility; Myosin light chain kinase; Serotonin system