山羊单纯与复合全身麻醉效果的比较

目的对比山羊单纯麻醉与复合麻醉的效果,探讨一种安全高效便捷的山羊麻醉方法。方法选取山羊30只,随机分为A、B、C三组,A组给予单纯戊巴比妥钠麻醉,B组给予单纯氯胺酮麻醉,C组给予地西泮、戊巴比妥钠和氯胺酮复合麻醉,记录三种麻醉方法的起效时间、麻醉维持时间、麻醉药物用量及麻醉死亡率。结果地西泮、戊巴比妥钠和氯胺酮复合麻醉,起效快、麻醉维持时间长、动物死亡率低、麻醉效果好。结论安定、戊巴比妥钠和氯胺酮复合麻醉优于单纯麻醉,是一种高效、便捷、安全山羊全身麻醉方法。     

An apparatus for anesthetizing small laboratory animals.

A simple apparatus was designed for simultaneous general anesthesia of a number of small laboratory animals with spontaneous respiration. Anesthesia is consistent over many hr. The apparatus consists of an oxygen tank and vaporizer, a glass distribution bottle, and a non-return circuit of separate inspiratory and expiratory valves for each animal. The equipment is inexpensive to construct and can be rapidly adjusted for exact control of gas flow and anesthetic depth.     

Effects of general anesthetics on the bacterial luciferase enzyme from Vibrio harveyi: an anesthetic target site with differential sensitivity

The effects of a diverse range of 36 general anesthetics and anesthetic-like compounds on a highly purified preparation of the bacterial luciferase enzyme from Vibrio harveyi have been investigated. Under conditions where the flavin site was saturated, almost all of the anesthetics inhibited the peak enzyme activity and slowed the rate of decay. However, a small number of the more polar agents only inhibited at high concentrations, while stimulating activity at lower concentrations. The inhibition was found to be competitive in nature, with the anesthetics acting by competing for the binding of the aldehyde substrate n-decanal. The anesthetic binding site on the enzyme could accommodate only a single molecule of a large anesthetic but more than one molecule of a small anesthetic, consistent with the site having circumscribed dimensions. The homologous series of n-alcohols and n-alkanes exhibited cutoffs in inhibitory potency, but these cutoffs occurred at very different chain lengths (about C10 for the n-alkanes and C15 for the n-alcohols), mimicking similar cutoffs observed for general anesthetic potencies in animals. Binding constants determined from peak height measurements showed that the inhibitor binding site was predominantly hydrophobic (with a mean delta delta G CH2 of -5.0 kJ/mol), but fluctuations in the binding constants with chain length revealed regions in the binding site with polar characteristics. Binding constants to an intermediate form of the enzyme (intermediate II) were also determined, and these confirmed the principal features of the binding site deduced from the peak height measurements. The long-chain compounds, however, bound considerably tighter to the intermediate II form of the enzyme, and this was shown to account for the biphasic decay kinetics that were observed with these compounds. Overall, there was poor agreement between the EC50 concentrations for inhibiting the luciferase enzyme from V. harveyi and those which induce general anesthesia in animals, with bulky compounds being much less potent, and moderately long chain alcohols being much more potent, as luciferase inhibitors than as general anesthetics.     

常用麻醉剂对麻醉小鼠超声心功能的影响

目的:比较常见的多种麻醉剂对小鼠心脏超声结果的影响。方法:C57BL/6小鼠25只,随机分5组,每组5只。首先在清醒状态下,借助小动物高频超声系统(Vevo2100)评价小鼠心功能,然后分别用戊巴比妥钠、水合氯醛、三溴乙醇、氯胺酮/地西泮及异氟烷麻醉,再次对心功能进行评价。比较6种不同处理情况下,超声反映的小鼠心功能的差异。结果:与清醒状态相比,5种麻醉方式下,小鼠的心率及心功能均有不同程度降低。其中,戊巴比妥钠、水合氯醛、三溴乙醇及异氟烷麻醉组的左心收缩功能显著降低(P0.01),而氯胺酮/地西泮麻醉的小鼠与清醒组相比,收缩功能无明显差异(P0.05),但其余参数也有显著差异(P0.01)。结论:不论何种麻醉方式,都会对小鼠心率及心功能造成一定影响,但其同组内仍具有可比性;因此应根据现实条件及实验需要选择麻醉剂,并贯彻始终,保持试验中麻醉条件的一致性。     

Anesthesia and other considerations for in vivo imaging of small animals

The use of small animal imaging is increasing in biomedical research thanks to its ability to localize altered biochemical and physiological processes in the living animal and to follow these processes longitudinally and noninvasively. In contrast to human studies, however, imaging of small animals generally requires anesthesia, and anesthetic agents can have unintended effects on animal physiology that may confound the results of the imaging studies. In addition, repeated anesthesia, animal preparation for imaging, exposure to ionizing radiation, and the administration of contrast agents may affect the processes under study. We discuss this interplay of factors for small animal imaging in the context of four common imaging modalities for small animals: positron emission tomography (PET) and single photon emission computed tomography (SPECT), computed tomography (CT), magnetic resonance imaging (MRI), and optical imaging. We discuss animal preparation for imaging, including choice of animal strain and gender, the role of fasting and diet, and the circadian cycle. We review common anesthesias used in small animal imaging, such as pentobarbital, ketamine/xylazine, and isoflurane, and describe techniques for monitoring the respiration and circulation of anesthetized animals that are being imaged as well as developments for imaging conscious animals. We present current imaging literature exemplifying how anesthesia and animal handling can influence the biodistribution of PET tracers. Finally, we discuss how longitudinal imaging studies may affect animals due to repeated injections of radioactivity or other substrates and the general effect of stress on the animals. In conclusion, there are many animal handling issues to consider when designing an imaging experiment. Reproducible experimental conditions require clear, consistent reporting, in the study design and throughout the experiment, of the animal strain and gender, fasting, anesthesia, and how often individual animals were imaged.     

Effect of anesthetic agents on lavage fluid parameters used as indicators of pulmonary injury

The effect of the anesthetic agent used in killing animals in an in vivo pulmonary toxicity screening test was examined in Fischer-344 rats and in Syrian hamsters. Using animals killed by cervical dislocation with no anesthesia as a baseline, two types of anesthetic agents (halothane, sodium pentobarbital) and carbon dioxide were tested. Carbon dioxide caused the greatest perturbance of baseline lavage fluid and tissue parameters normally used in the screening test. Halothane anesthesia caused the least perturbance in the screening test parameters and was selected as the anesthetic of choice for use in future pulmonary toxicity tests.     

Effects of an anesthetic mixture of medetomidine,midazolam, and butorphanol in rats—strain difference and antagonism by atipamezole

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.     

Comparison of Isoflurane and Carbon Dioxide Anesthesia in Chilean Rose Tarantulas (Grammostola rosea)

This study investigated the use of two anesthetic agents, isoflurane and carbon dioxide, in Chilean rose tarantulas (Grammostola rosea). We compared the onset, duration of anesthesia, and recovery time with both gases, and made observations regarding the effects of the anesthetic protocols. Subjectively, episodes for the isoflurane animals were uneventful. The spiders were calm throughout and did not respond adversely to gas exposure. Conversely, animals anesthetized with carbon dioxide experienced violent inductions and recoveries; the tarantulas appeared agitated when the carbon dioxide flow began. Seizure‐like activity and defecation would frequently be noted prior to induction with carbon dioxide. Neither isoflurane nor carbon dioxide seemed to have any clinically apparent short‐ or long‐term impact. The animals were all normal for at least 1‐year postexperiment. Future studies should focus on defining the impact, if any, that these anesthetic agents have on the health of invertebrate species. Zoo Biol. 32:101‐103, 2013. © 2012 Wiley Periodicals, Inc.     

Impact of ether anesthesia on the hypophyseal content of oxytocin neurophysin I and II: a comparative study with ketamine in the rat

The effect of anesthetic stress on the major hormones of the posterior pituitary (PP), such as oxytocin (OT), oxytocin-neurophysin (OTNP-I) and its metabolic product, OTNP-II, was studied. Rats were treated with either a combination of atropine (0.87 mg/kg) and diphenylhydantoin (85 mg/kg) and then anesthetized with ketamine (42 mg/kg) or were directly anesthetized with diethyl-ether, and then killed. Controls were killed with a laboratory guillotine. Our study revealed that 1.) animals killed with a guillotine or being medicated with our drug combination prior to sacrifice had similar concentrations of OT, OTNP-I and OTNP-II per PP and ml of blood; 2.) animals anesthetized with either prior to sacrifice had a decreased concentration of neuropeptides per PP; the blood concentration of OT was 1.6 times higher than in animals treated with the drug combination or killed directly with a guillotine. In addition plasma concentrations of OTNP-I and OTNP-II were above the baseline. We conclude that ether is not an adequate anesthetic for studying the neurophysins from the PP in vivo. Treatment of animals with atropine and diphenylhydantoin in combination with ketamine does not alter the profile of the major hormones from the PP during anesthetic stress.     

Pentobarbital inhibits the billiary excretion of organic acids: a study with succinysulfathiazole in the rat.

The present study was undertaken to determine whether the use of pentobarbital as an anesthetic reduces the biliary excretion of acidic drugs in rats. The drug chosen for the experiment was succinylsulfathiazole, a compound excreted unmetabolized in the bile. Animals anesthetized with urethane excreted 22.1% of the dose in the bile as compared to only 8.4% for the same time period in pentobarbital anesthetized animals. The choice of anesthetic did not affec the bile flow but did influence the bile/liver concentration gradient of succinylsulfathiazole, with the pentobarbital treated rats demonstrating a significantly lower value. Despite the higher biliary excretion of succinylsulfathiazole in the urethane treated rats, the total amount in the bile plus urine was 60% of the dose in the urethane anesthetized animals as compared with 62% in the pentobarbital treated rats. These results suggest that pentobarbital reduced the hepatic transport of succiylsulfathiazole into the bile. The question whether urethane is a preferred anesthetic for biliary excretion studies warrants further investigation.     

Effect of hydrostatic pressure on halothane-induced depression of mitochondrial respiration

Anesthetized animals are awakened when subjected to increased atmospheric pressure. Whether all phenomena associated with the anesthetic state are similarly reversed is not known. Since the anesthetic halothane produces a dose-related reversible depression of rat liver mitochondrial respiration, the effect of 51 atmospheres of pressure on the drug's action was evaluated. It is concluded that application of pressure does not antagonize the inhibition produced by this anesthetic.     

Evaluation of anesthetic protocol for the collection of semen from captive collared peccaries (Tayassu tajacu) by electroejaculation

The objective of this study is to verify and compare the effects of acepromazine–tiletamine–zolazepam and propofol used in anesthetic protocols for semen collection by electroejaculation from captive collared peccaries. Ten sexually mature animals were physically restrained and anesthetized by either intravenous administration of tiletamine–zolazepam (2 mg/kg) after acepromazine premedication, or a propofol dose of 5 mg/kg. The onset of anesthetic recovery was determined by the animals regaining consciousness and attempting to stand. Semen was collected by electroejaculation and evaluated for volume, pH, sperm concentration, progressive motility, morphology, percentage of live cells and functional membrane integrity. Six anesthetized animals with the acepromazine–tiletamine–zolazepam protocol showed erection, but semen could be collected in only four (40%) attempts. Of the animals anesthetized using propofol, nine showed erection, and the ejaculates were collected in eight (80%) attempts. Furthermore, propofol afforded rapid recovery of animals, and ejaculates with enhanced sperm motility and functional membrane integrity as compared with those collected by the other protocol (P < 0.05). In conclusion, use of propofol for anesthetic restraint of collared peccaries enhanced collection of semen by electroejaculation.     

Overview movement as an index of anesthetic depth in humans and experimental animals

Anesthesia is used widely in animal research, but there are diverse opinions regarding acceptable anesthetic depth. Excessive anesthesia is associated with increased morbidity and mortality. Traditionally, researchers have been taught that animal movement during surgical and experimental procedures indicates that the animal is 'underanesthetized.' Complex movement, however, can be initiated and propagated within the spinal cord, with little input from supraspinal structures. For example, frogs with high spinal-cord transections still maintain the wiping reflex, whereby the hindlimb can move to the forelimb to wipe away a noxious stimulus. Rats that have been decerebrated can perform complex tasks, such as grooming. Brain-dead humans can have spontaneous movement of the arms, legs, and head. Consistent with these phenomena, emerging evidence suggests that, in anesthetized animals, movement in response to noxious stimulation is abolished primarily via anesthetic action in the spinal cord. When isoflurane, halothane, or thiopental is delivered selectively to the brain circulation in goats, substantially greater anesthetic concentrations in brain are needed to ablate movement, as compared with those required upon delivery of anesthetic to the entire body. Rats that have had a precollicular decerebration require the same isoflurane concentrations to prevent movement as compared to intact rats. Furthermore, data from both humans and animals indicate that memory and awareness are ablated at anesthetic concentrations that are < 50% of those needed to abolish movement. Collectively, these data indicate that animals can be anesthetized at depths that, although they do not abolish movement, still produce unconsciousness and amnesia.     

Structural basis for the inhibition of firefly luciferase by a general anesthetic.

The firefly luciferase enzyme from Photinus pyralis is probably the best-characterized model system for studying anesthetic-protein interactions. It binds a diverse range of general anesthetics over a large potency range, displays a sensitivity to anesthetics that is very similar to that found in animals, and has an anesthetic sensitivity that can be modulated by one of its substrates (ATP). In this paper we describe the properties of bromoform acting as a general anesthetic (in Rana temporaria tadpoles) and as an inhibitor of the firefly luciferase enzyme at high and low ATP concentrations. In addition, we describe the crystal structure of the low-ATP form of the luciferase enzyme in the presence of bromoform at 2.2-A resolution. These results provide a structural basis for understanding the anesthetic inhibition of the enzyme, as well as an explanation for the ATP modulation of its anesthetic sensitivity.     

Equilibration of Halothane with Brain Tissue In Vitro: Comparison to Brain Concentrations During Anesthesia

A method was devised for reproducing anesthetic concentrations of halothane in slice and membrane preparations of rat brain in vitro. Rats were anesthetized with varying concentrations of halothane, responsiveness was tested, and brain halothane content was determined by heptane extraction and gas chromatography. The inspired concentration of halothane at which half of all animals were unresponsive was 1.05%. At 1.25% halothane, all animals were unresponsive and brain halothane was determined to be 41 +/- 1.3 nmol/mg lipid. No significant differences in halothane concentration between whole brain and a variety of brain regions were detected. To obtain similar concentrations in vitro, membranes or slices of cerebral cortex were incubated in Krebs-Ringer bicarbonate buffer (KRB) that had been preequilibrated with anesthetic. Halothane equilibrated rapidly with the buffer and the tissues. The partition coefficient between gas and KRB was found to be 0.78, and between brain slices and KRB approximately 12. Slightly lower gas concentrations were necessary in vitro than in vivo to obtain the same tissue levels of anesthetic. Using this method, it was shown that there was no effect of anesthetic concentrations of halothane on the uptake of [3H]norepinephrine or [3H]choline into slices of rat cerebral cortex.     

Anesthetic effects of a three-drugs mixture —comparison of administrative routes and antagonistic effects of atipamezole in mice—

The anesthetic mixture of medetomidine (MED), midazolam (MID) and butorphanol (BUT) produced anesthetic duration of around 40 minutes (min) in ICR mice. We reported that this anesthetic mixture produced almost the same anesthetic effects in both male and female BALB/c and C57BL/6J strains. Intraperitoneal (IP) administration of drugs has been widely used in mice. However, various injectable routes of the anesthetic mixture may cause different anesthetic effects. First, we examined effects of the anesthetic mixture by subcutaneous (SC) and intravenous (IV) injection compared to IP injection. After injection of the anesthetic mixture, administration of atipamezole (ATI) induced mice recovery from anesthesia. Secondly, we examined how different dosage and optimum injection timing of ATI affected mice recovery from anesthesia. We used an anesthetic score to measure anesthetic duration and a pulse oximeter to monitor vital signs under anesthesia. Usually, drugs from SC injection work more weakly than IP or IV injection. However, we found no significant differences of anesthetic duration among the three different injection routes. Antagonistic effects of ATI (0.3 mg/kg and 1.5 mg/kg) worked equally when administered at 30 min after injection of the anesthetic mixture. Antagonistic effects of ATI (1.5 mg/kg) were stronger than ATI (0.3 mg/kg) at 10 min after injection of the anesthetic mixture. The anesthetic mixture is a useful drug to induce nearly the same anesthetic effects by different injection routes and has an antagonist of ATI which helps mice quickly recover from anesthesia. These results may contribute to the welfare of laboratory animals.     

Propofol anesthesia in loggerhead (Caretta caretta) sea turtles

Rapid, safe, and effective methods of anesthetic induction and recovery are needed for sea turtles, especially in cases eligible for immediate release. This study demonstrates that intravenous propofol provides a rapid induction of anesthesia in loggerhead (Caretta caretta) sea turtles and results in rapid recovery, allowing safe return to water shortly after the procedure. Forty-nine loggerhead sea turtles were recovered as local fishery by-catch in pound nets and transported to a surgical suite for laparoscopic sex determination. Treatment animals (n = 32) received 5 mg/kg propofol intravenously (i.v.) as a rapid bolus, whereas control animals (n = 17) received no propofol. For analgesia, all animals received a 4 ml infusion of 1% lidocaine, locally, as well as 2 mg/kg ketoprofen intramuscularly (i.m.). Physiologic data included heart and respiratory rate, temperature, and a single blood gas sample collected upon termination of the laparoscopy. Subjective data included jaw tone and ocular reflex: 3 (vigorous) to 0 (none detected). Anesthetic depth was scored from 1, no anesthesia, to 3, surgical anesthesia. Turtles receiving propofol became apneic for a minimum of 5 min with a mean time of 13.7 +/- 8.3 min to the first respiration. Limb movement returned at a mean time of 21.1 +/- 16.8 min. The treatment animals were judged to be sedated for approximately 30 min (mean anesthetic depth score > or = 1.5) when compared to controls. Median respiratory rates for treatment animals were slower compared to controls for the first 15 min, then after 35 min, they became significantly faster than the controls. Median heart rates of control animals became significantly slower than treatment animals between 40 and 45 min. Physiologic differences between groups persisted a minimum of 55 min. Possible explanations for heart rate and respiratory rate differences later in the monitoring period include a compensatory recovery of treatment animals from anesthesia-induced hypoxia and hypercapnia or, alternatively, an induced response of the nonsedated control animals. The animals induced with propofol were easier to secure to the restraint device and moved less during laparoscopy. In conclusion, propofol is a safe and effective injectable anesthetic for use in free-ranging loggerhead sea turtles that provides rapid induction and recovery.     

Anesthetic and supportive management during experimental pulsatile flow perfusion studies in calves

The purpose of this study was to determine the factors influencing successful experimental cardiopulmonary bypass studies using pulsatile flow perfusion and the medications and methodology necessary to produce successful bypass in calves. In six calves showing no cardiopulmonary pathology prior to bypass procedures, successful anesthesia and surgical intervention was accomplished. Animals were maintained on 5 hours of pulsatile flow bypass perfusion. Successful recovery from the procedures was accomplished. In two calves with pre-existing pulmonary pathology, anesthetic and surgical intervention was accomplished with the utilization of extensive anesthetic management and cardiac supportive medications until the animals could be initiated into 5 hours of pulsatile flow bypass perfusion, in spite of major pulmonary dysfunction. In these two animals, attempts to resuscitate upon termination of pulsatile flow perfusion were unsuccessful due to pre-existing excessive lesions in the lungs. This study shows a contrast between complete success of a pulsatile flow system in normal subjects versus the ultimate failure in experimental animals with pre-existing pulmonary pathology. The inability of experimental calves with a diseased lung to resume spontaneous cardiopulmonary function after the challenges of thoracic intervention indicates the unsuitability of animals with marked pre-existing pulmonary disease status for use in cardiopulmonary bypass studies.     

Preliminary comments on a redescription of Pseudolithophyllum fuegianum and Titanoderma conspectum (Rhodophyta,Corallinales) in Tierra del Fuego,Argentina

The effect of twelve drugs and chemical compounds on the narcosis of Brachionus plicatilis was studied using standardized laboratory conditions. Drug efficacy was compared by calculating EC₅₀ (effective concentration causing narcosis in 50% of animals), time necessary to reach narcosis in 50% of animals, concentration range of activity, and degree of extension after preservation. The local anesthetic Bupivacaine was found to be most effective by all criteria. Our previous data and preliminary field experiments indicated that drug sensitivity varies widely, even between congeneric taxa. The anesthetic effect of carbonated water was also investigated.     

Use of two anesthetic combinations for semen collection by electroejaculation from captive coatis (Nasua nasua)

The objective was to compare the effects of ketamine-xylazine or tiletamine-zolazepam combinations as anesthetic protocols for captive coatis (Nasua nasua) for semen collection by electroejaculation. Five mature male coatis were physically restrained and then anesthetized by im injections of ketamine (10 mg/kg) plus xylazine (1 mg/kg) or a tiletamine-zolazepam combination (8 mg/kg). For the two combinations, additional quarter-doses of ketamine or the tiletamine-zolazepam combination were administered when necessary. Semen was collected by electroejaculation and immediately evaluated for color, volume, pH, sperm motility, vigor, morphology, acrosomal integrity, and percentage of live cells. Overall, collection of nine ejaculates was attempted from five animals for each treatment. Regardless of the anesthetic combination, all animals developed an erection during each attempt to collect semen. Ejaculates were obtained in all (9 of 9) attempts that used ketamine-xylazine for anesthesia, but in only 3 of 9 attempts (P < 0.05) when tiletamine-zolazepam was used. All ejaculates contained sperm, with no significant differences in semen characteristics between the two anesthetic combinations. Recovery was smooth in all animals. In conclusion, semen collection by electroejaculation in coatis was significantly more successful with the use of a ketamine-xylazine combination than with tiletamine-zolazepam.