title: Stimulation of contractions in pregnant human myometrium is associated with 5-HT3 receptors.
abstract: BACKGROUND
  Serotonin (5-HT) is known to play an important role in regulating uterine contractions. However, the specific receptors involved have not been well characterized. We evaluated whether 5-HT3 receptors exist in human myometrium, and their effects on myometrial contractility when stimulated by a 5-HT3 agonist.
  
  
  METHODS
  Four tissue samples taken from patients undergoing hysterectomy (n=2) and elective cesarean delivery (n=2) were used to detect expression of 5-HT3 receptors on the myometrium using western blotting. For isometric tension measurement, another 12 myometrial strips obtained from patients undergoing elective cesarean delivery were randomly divided into a control group (Group CON) and an RS56812 group (Group RG). In increasing doses from 10-7M to 10-4M, RS56812, a 5-HT3 receptor agonist, was used to investigate the contractile effects after bonding to the 5-HT3 receptor, following which the effects of granisetron were assessed. Amplitude, interval and duration of myometrial contractions were recorded.
  
  
  RESULTS
  Proteins with a molecular mass of 55kDa, consistent with 5-HT3 receptors, were detected both on non-pregnant and late-pregnant human uteri. RS56812 increased the contractile amplitude at concentrations of 10-6M, 10-5M and 10-4M, achieving maximum effect at 10-5M. A prolonged contractile interval was detected at the concentration of 10-4M. However, RS56812 showed no significant effect on contraction duration. Granisetron did not reverse the contractile effects induced by RS56812.
  
  
  CONCLUSIONS
  5-HT3 receptors are expressed on non-pregnant and pregnant uteri. RS56812 enhanced myometrial contractions, but this was not affected by granisetron, the mechanism of which requires further investigation.
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China.
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China.
authors.forename: M
authors.initials: M
authors.lastname: Diao
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China.
authors.forename: J
authors.initials: J
authors.lastname: Ni
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China.
authors.forename: P
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Anesthesiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Wan
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China. Electronic address: mayushan_123@163.com.
authors.forename: Y S
authors.initials: YS
authors.lastname: Ma
authors.affiliation: Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China; Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, Sichuan, China. Electronic address: xuemeilinscu@163.com.
authors.forename: X M
authors.initials: XM
authors.lastname: Lin
mesh_terms: D015153:Blotting, Western; D005260:Female; D006801:Humans; D009215:Myometrium / Q000502:physiology*; D011247:Pregnancy; D044406:Receptors, Serotonin, 5-HT3 / Q000235:genetics / Q000502:physiology*; D014590:Uterine Contraction / Q000235:genetics / Q000502:physiology*
chemical_list: D044406:Receptors, Serotonin, 5-HT3
keywords: 5-HT3 receptor; Contraction; Granisetron; Myometrium; RS56812