title: The effects of anesthesia on the biodistribution of drugs in rats: a carboplatin study.
abstract: OBJECTIVE
  Anesthetics can alter the biodistribution profile of drugs and, consequently, the regional pharmacokinetics of antineoplastic drugs at the tumor site. The effect of coadministered anesthetics on the biodistribution profile of carboplatin was studied in rats.
  
  
  METHODS
  Female Wistar rats were used to compare the effects of ketamine/xylazine, thiopental and pentobarbital on the biodistribution of 30 mg/kg radiolabelled 195mPt-carboplatin administered intravenously, with conscious rats as the control group. Blood and urine samples were collected between 5 and 120 min.
  
  
  RESULTS
  The percentage values of the injected dose of platinum per ml (%ID/ml) in plasma at the final time-point were respectively, 0.557%, 0.156%, 0.115% and 0.086%, in pentobarbital-, ketamine/xylazine- and thiopental-injected rats, and in conscious animals. Following the same sequence of groups, the %ID/ml values of platinum in the cumulative urine were 0.001%, 0.619%, 0.184% and 0.118%, respectively. Urine output varied from very little in the pentobarbital group, to several milliliters in the other groups.
  
  
  CONCLUSIONS
  There was an increase of almost 100-fold in total platinum uptake in the kidneys, cerebrum and cerebellum of rats receiving pentobarbital over the uptake in the control rats, whereas the biodistribution profile of the thiopental group had the least variance. These results demonstrate the importance of anesthetic selection in animal pharmacokinetic studies, as it influences the biodistribution and pharmacokinetic profile of the drug being studied.
authors.affiliation: Department of Pharmaceutical Sciences, University of Southern California, Los Angeles, USA. sancho@hsc.usc.edu
authors.forename: A R
authors.initials: AR
authors.lastname: Sancho
authors.forename: J A
authors.initials: JA
authors.lastname: Dowell
authors.forename: W
authors.initials: W
authors.lastname: Wolf
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D000970:Antineoplastic Agents / Q000493:pharmacokinetics*; D016190:Carboplatin / Q000493:pharmacokinetics*; D002531:Cerebellum / Q000378:metabolism; D004347:Drug Interactions; D005260:Female; D007668:Kidney / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution
chemical_list: D000777:Anesthetics; D000970:Antineoplastic Agents; D016190:Carboplatin