title: Volatile anesthetics decrease peristalsis in the guinea pig ureter.
abstract: BACKGROUND
  The origin of renal dysfunction associated with anesthesia and surgery is complex and incompletely understood. The effects of the volatile anesthetic agents isoflurane, enflurane, and halothane on the renal pacemaker and ureteral peristalsis may play an important role.
  
  
  METHODS
  Guinea pig ureter and pelvis were dissected and placed in a sample chamber that allowed immersion in a temperature-controlled bath with gas (O2 with or without volatile agent) bubbled through the chamber continuously. The baseline frequency and amplitude of peristaltic contractions were measured on a polygraph recorder. The preparations were then exposed to up to 4 vol% volatile agent incrementally to generate a cumulative dose-response curve, and the subsequent frequency of peristaltic contractions was determined. The concentration of the volatile agent in solution was measured by gas chromatography.
  
  
  RESULTS
  There was a significant dose-related decrease in the frequency of ureteral contractions for all three agents. A statistical model relating percentage baseline frequency to millimolar concentrations of volatile anesthetics showed that halothane produced a more pronounced decrease in frequency than did isoflurane or enflurane. However, the decrease was directly related to the MAC multiples and did not differ for the three agents.
  
  
  CONCLUSIONS
  Ureteral peristaltic contractions are decreased in a dose-dependent manner by enflurane, halothane and isoflurane.
authors.affiliation: Department of Anesthesia and Critical Care, University of Chicago, Illinois 60637.
authors.forename: C J
authors.initials: CJ
authors.lastname: Young
authors.forename: A
authors.initials: A
authors.lastname: Attele
authors.forename: A
authors.initials: A
authors.lastname: Toledano
authors.forename: R
authors.initials: R
authors.lastname: Núñez
authors.forename: J
authors.initials: J
authors.lastname: Moss
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004737:Enflurane / Q000494:pharmacology*; D006168:Guinea Pigs; D006221:Halothane / Q000494:pharmacology*; D066298:In Vitro Techniques; D007530:Isoflurane / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D014513:Ureter / Q000187:drug effects* / Q000502:physiology
chemical_list: D004737:Enflurane; D007530:Isoflurane; D006221:Halothane