title: Effects of an anesthetic mixture of medetomidine, midazolam, and butorphanol in rats-strain difference and antagonism by atipamezole.
abstract: An anesthetic mixture of medetomidine (MED), midazolam (MID), and butorphanol (BUT) has been used in laboratory animals. We previously reported that this anesthetic mixture produced closely similar anesthetic effects in BALB/c and C57BL/6J strains. We also demonstrated the efficacy of atipamezole (ATI), an antagonist of MED that produced quick recovery from anesthesia in mice. Anesthetics have various anesthetic effects among animal strains. However, the differences in the effects of anesthetic mixtures in rats are unclear. In the present study, we first examined effects of the abovementioned anesthetic mixture using three different rat strains: Wistar (WST), Sprague-Dawley (SD), and Fischer 344 (F344). Second, we examined how different dosages and optimum injection timing of ATI affected recovery from anesthesia in rats. We used the anesthetic score to measure anesthetic duration and a pulse oximeter to monitor vital signs. We found no significant differences in anesthetic duration among the three different strains. However, recovery from anesthesia in the SD strain took significantly longer than in the other strains. The antagonistic effects of ATI (0.15 mg/kg and 0.75 mg/kg) were equivalent when administered at 30 min after anesthetic mixture administration. The antagonistic effects of ATI 0.75 mg/kg were stronger than those of ATI 0.15 mg/kg at 10 min after anesthetic mixture administration. This anesthetic mixture is a useful drug that can induce similar anesthetic effects in three different strains and has an antagonist, ATI, that makes rats quickly recover from anesthesia. These results may contribute to the welfare of laboratory animals.
authors.affiliation: Department of Experimental Animals, Interdisciplinary Center for Science Research, Organization for Research, Shimane University, 89-1 Enya-cho, Izumo, Shimane 693-8501, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kirihara
authors.forename: Mayumi
authors.initials: M
authors.lastname: Takechi
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurosaki
authors.forename: Yuta
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Yoji
authors.initials: Y
authors.lastname: Saito
authors.forename: Takashi
authors.initials: T
authors.lastname: Takeuchi
mesh_terms: D000762:Anesthesia Recovery Period; D019162:Anesthetics, Combined / Q000494:pharmacology*; D000818:Animals; D002077:Butorphanol / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D020926:Medetomidine / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D008874:Midazolam / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D010092:Oximetry; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D019162:Anesthetics, Combined; D007093:Imidazoles; C050701:atipamezole; D020926:Medetomidine; D002077:Butorphanol; D008874:Midazolam