title: Evaluation of two combinations of Domitor, Zoletil 100, and Euthatal to obtain long-term nonrecovery anesthesia in Sprague-Dawley rats.
abstract: We sought to evaluate a new protocol designed to maintain long-term, nonrecovery, surgical anesthesia in Sprague-Dawley rats. In the first phase, two groups of rats were anesthetized with two different dose combinations of Domitor (medetomidine) and Zoletil 100 (tiletamine-zolazepam) to investigate their efficacy in induction of anesthesia. One combination comprised Domitor at 35 microg/kg and Zoletil 100 at 40 mg/kg, whereas the other comprised Domitor at 50 microg/kg and Zoletil 100 at 20 mg/kg. Both combinations effectively induced deep anesthesia and caused no mortality, but the duration of anesthesia differed statistically. In the second phase, we induced anesthesia with both Domitor-Zoletil 100 dose combinations then investigated the possibility of maintaining anesthesia for 5 h by administering Euthatal (pentobarbitone) intra-arterially at 10 mg/kg hourly. Depth of anesthesia, mortality, physiological parameters, blood gas analysis, hematology, clinical chemistry, and postmortem histopathology were recorded. Euthatal provided stable long-term anesthesia with both dose combinations of Domitor-Zoletil 100. Seven of 8 (88%) animals anesthetized with Domitor at 50 microg/kg and Zoletil 100 at 20 mg/kg successfully were maintained under deep anesthesia for 5 h. Higher mortality (36% versus 12%) occurred in group of animals treated with Domitor at 35 microg/kg and Zoletil 100 at 40 mg/kg. This difference may be linked to dose-related respiratory depression, as alterations of arterial gas levels were noted. Our findings suggest that, when long-term nonrecovery anesthesia is required, doses of 50 microg/kg Domitor and 20 mg/kg Zoletil 100 are preferable when given with Euthatal to maintain physiological conditions in animals.
authors.affiliation: Laboratory Animal Science Department, GlaxoSmithKline Medicine, Research Centre, Via Fleming 4, 37135, Verona, Italy.
authors.forename: Livia
authors.initials: L
authors.lastname: Ferrari
authors.forename: Giuliano
authors.initials: G
authors.lastname: Turrini
authors.forename: Chiara
authors.initials: C
authors.lastname: Rostello
authors.forename: Alessia
authors.initials: A
authors.lastname: Guidi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Casartelli
authors.forename: Alessandro
authors.initials: A
authors.lastname: Piaia
authors.forename: Matteo
authors.initials: M
authors.lastname: Sartori
mesh_terms: D000758:Anesthesia / Q000662:veterinary*; D000778:Anesthetics, Dissociative; D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D001831:Body Temperature / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D022781:Hepatocytes / Q000187:drug effects / Q000473:pathology; D006993:Hypnotics and Sedatives; D007103:Immobilization / Q000662:veterinary; D007269:Injections, Intra-Arterial / Q000662:veterinary; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008136:Longevity / Q000187:drug effects; D008168:Lung / Q000187:drug effects / Q000473:pathology; D008297:Male; D020926:Medetomidine; D010424:Pentobarbital; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects; D013047:Specific Pathogen-Free Organisms; D013992:Tiletamine; D015041:Zolazepam
chemical_list: D000778:Anesthetics, Dissociative; D004338:Drug Combinations; D006993:Hypnotics and Sedatives; C006131:tiletamine, zolazepam drug combination; D013992:Tiletamine; D015041:Zolazepam; D010424:Pentobarbital; D020926:Medetomidine