Anesthetic effects of a combination of medetomidine, midazolam and butorphanol on the production of offspring in Japanese field vole, <i>Microtus montebelli</i>

Abstract

Pentobarbital sodium (Somnopentyl) can induce surgical anesthesia with a strong hypnotic effect that causes loss of consciousness. Animals have been known to die during experimental surgery under anesthesia with Somnopentyl, causing it to be declared inadequate as a general anesthetic for single treatment. An anesthetic combination of 0.3 mg/kg medetomidine, 4.0 mg/kg midazolam and 5.0 mg/kg butorphanol (M/M/B:0.3/4/5) was reported to induce anesthesia for a duration of around 40 min in ICR mice; similar anesthetic effects were reported in both male and female BALB/c and C57BL/6J strains of mice. However, the anesthetic effects of this combination in Japanese field vole, Microtus montebelli, remain to be evaluated. In the present study, we assessed the effects of Somnopentyl and different concentrations of anesthetic combination (M/M/B:0.3/4/5, 0.23/3/3.75 or 0.15/2/2.5) in Japanese field voles, by means of anesthetic scores. We also examined effect of these anesthetics on production of offspring. Death of the animals was observed only with Somnopentyl. The anesthetic score of Somnopentyl was lower than those of the other anesthetics, although there were no significant differences in duration, body weight and frequency of respiratory among the evaluated anesthetics. Abortion rate with Somnopentyl was significantly higher than that with the M/M/B:0.23/3/3.75 combination, although there was no significant difference in the number of offspring between two. In conclusion, results of this study provide basic information for achieving appropriate anesthetic concentrations in addition to indicating a new, safe and effective surgical anesthetic for Japanese field voles.

Evaluation of injectable anaesthesia with five medetomidine-midazolam based combinations in Egyptian fruit bats (Rousettus aegyptiacus)

“…Female bats should be studied too, because they could potentially respond differently to the anaesthetic protocols, as was reported in other species. 42 In conclusion, all five examined protocols in this study induced anaesthesia in adult male bats with no apparent morbidity or mortality, and could potentially replace inhalation anaesthesia. Choice of optimal combination would depend on the exact procedure and setting.…”

“…Twitching usually started shortly after the first signs of ataxia, and generally lasted for approximately 20 min, until the bats reached a deeper anaesthetic plane. This side-effect may be specific to Egyptian fruit bats, as it was not reported in other species under MM-Fen or MM-But anaesthesia, 24,41,42 although muscle twitching following sedation with medetomidine was described in dogs and cats. 43 Wing flapping was reported in bats in response to ketamine administration, 13 and may be similar to the phenomenon that we described as twitching.…”

“…Female bats should be studied too, because they could potentially respond differently to the anaesthetic protocols, as was reported in other species. 42…”

Assisted reproductive technologies in Microtus genus

“…Following the injection of hCG, the female was doubling up with the vasectomized male to promote the coitus for infertile‐induced ovulation. Four to six hours after coitus, the female was anesthetized with the mixture of three anesthetics (0.23 mg/kg medetomidine hydrochloride, 3.00 mg/kg midazolam, and 3.75 mg/kg butorphanol), and then the aforementioned sperm suspension was directly transferred into each uterine horn by the transcervical method (2 × 10 6 cells/20 µl/uterine horn). After a treatment, female was treated with atipamezole and awakened.…”

Correlative volume-imaging using combined array tomography and FIB-SEM tomography with beam deceleration for 3D architecture visualization in tissue

“…Specimens were prepared as described in our previous studies [ 9 ‒ 14 ]. Mice (C57BL/6, 4 weeks old) were anesthetized using a mixture of three anaesthetics, namely medetomidine hydrochloride, midazolam and butorphanol [ 15 , 16 ]. The anaesthetic mixture was prepared by mixing 0.75 mL of medetomidine hydrochloride, 2 mL of midazolam and 2.5 mL of butorphanol, and the volume was made up to 25 mL with saline solution.…”