title: Blood gases and energy metabolites in mouse blood before and after cerebral ischemia: the effects of anesthetics.
abstract: The levels of blood gases and energy metabolites strongly influence the outcome of animal experiments, for example in experimental stroke research. While mice have become prominent animal models for cerebral ischemia, little information is available on the effects of anesthetic drugs on blood parameters such as blood gases, glucose and lactate in this species. In this work, we collected arterial and venous blood samples from female CD-1 mice before and after cerebral ischemia induced by middle cerebral artery occlusion (MCAO), and we tested the influence of different anesthetic drugs. We found that all of the injectable anesthetics tested (ketamine/xylazine, chloral hydrate, propofol and pentobarbital) caused a decrease in blood pH and partial pressure of oxygen (pO2) and an increase of partial pressure of carbon dioxide (pCO2), indicating respiratory depression. This was not observed with inhalable anesthetics such as isoflurane, sevoflurane and halothane. Significant and up to two-fold increases of blood glucose concentration were observed under isoflurane, halothane, ketamine/xylazine, chloral hydrate, and propofol anesthesia. Lactate concentration rose significantly by 2-3-fold during inhalation of isoflurane and halothane treatment, but decreased by more than 50% after administration of pentobarbital. Permanent cerebral ischemia induced respiratory acidosis (low pH and pO2, high pCO2) which was most prominent after 24 h. Postsurgical treatment with Ringer-lactate solution (1 mL, intraperitoneal) caused a recovery of blood gases to basal levels after 24 h. Use of isoflurane for surgery caused a minor increase of blood glucose concentrations after one hour, but a strong increase of blood lactate. In contrast, anesthesia with pentobarbital did not affect glucose concentration but strongly reduced blood lactate concentrations one hour after surgery. All values recovered at three hours after MCAO. In conclusion, anesthetic drugs have a strong influence on murine blood parameters, which should be taken into account in experiments in mice.
authors.affiliation: Department of Pharmacology, University of Frankfurt College of Pharmacy, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
authors.forename: Tina M
authors.initials: TM
authors.lastname: Schwarzkopf
authors.forename: Tobias
authors.initials: T
authors.lastname: Horn
authors.forename: Dorothee
authors.initials: D
authors.lastname: Lang
authors.forename: Jochen
authors.initials: J
authors.lastname: Klein
mesh_terms: D000777:Anesthetics / Q000008:administration & dosage*; D000818:Animals; D001774:Blood Chemical Analysis; D001786:Blood Glucose / Q000032:analysis*; D001790:Blood Physiological Phenomena / Q000187:drug effects*; D002545:Brain Ischemia / Q000503:physiopathology*; D002245:Carbon Dioxide / Q000097:blood*; D004195:Disease Models, Animal; D005260:Female; D007773:Lactates / Q000097:blood*; D051379:Mice; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure
chemical_list: D000777:Anesthetics; D001786:Blood Glucose; D007773:Lactates; D002245:Carbon Dioxide; D010100:Oxygen