title: In vivo comparison of the effects of bupivacaine and levobupivacaine on the pregnant rat myometrium using electrohysterogram.
abstract: OBJECTIVE
  The effect of local anesthetics on myometrial contractility during labor analgesia is debatable. We aimed to compare the effects of bupivacaine and levobupivacaine on rat uterine contractility in an in vivo setting.
  
  
  METHODS
  Electrical activities of 40 pregnant rat uteruses were recorded on electrohysterogram after dividing the rats into bupivacaine and levobupivacaine groups. Uterine contraction frequencies were recorded at each 5-min interval. The first 5-min recording was considered the control, which was immediately followed by intramyometrial administration of either bupivacaine or levobupivacaine. The recordings were continued for 30 min. The changes in frequencies at each time interval of the groups were compared with each other and the control recording.
  
  
  RESULTS
  The frequencies from both groups at each interval were lower than the control values, but not different between the groups. The frequencies of the bupivacaine group during the 5-10 min and 10-15 min intervals were lower than the control time interval, but no significant differences were present between the control and the other time intervals. However, no significant differences were found at any time interval for the levobupivacaine group.
  
  
  CONCLUSIONS
  Levobupivacaine led to less muscle relaxation compared to bupivacaine and may be a better option for labor analgesia and anesthesia considering uterine contractility.
authors.affiliation: Department of Anesthesiology and Reanimation, Duzce University School of Medicine, Duzce, Turkey.
authors.forename: Gursel
authors.initials: G
authors.lastname: Kaynak
authors.forename: Abdulkadir
authors.initials: A
authors.lastname: Iskender
authors.forename: Mustafa
authors.initials: M
authors.lastname: Albayrak
authors.forename: Seyit
authors.initials: S
authors.lastname: Ankaralı
authors.forename: Serif
authors.initials: S
authors.lastname: Demir
authors.forename: Yavuz
authors.initials: Y
authors.lastname: Demiraran
authors.forename: Gulbin Sezen
authors.initials: GS
authors.lastname: Yalcın
mesh_terms: D016362:Analgesia, Obstetrical; D000773:Anesthesia, Obstetrical; D000779:Anesthetics, Local / Q000008:administration & dosage*; D000818:Animals; D002045:Bupivacaine / Q000008:administration & dosage* / Q000031:analogs & derivatives; D004594:Electrophysiology; D005260:Female; D000077554:Levobupivacaine; D011247:Pregnancy; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects*
chemical_list: D000779:Anesthetics, Local; D000077554:Levobupivacaine; D002045:Bupivacaine