BACKGROUND: The actions of mivacurium (MVC), a new benzylisoquinolinium nondepolarizing neuromuscular blockade, may be potentiated if preceded by succinylcholine (SCh). Additionally, the interaction between inhalational anesthetics and MVC has not yet been established in the cat. The effect of enflurane or isoflurane on the neuromuscular blocking action of MVC by preadministrated succinylcholine was evaluated. METHOD: Twelve cats, either sex, were assigned into two groups, based on the preadministration of succinylcholine (SCh) what about the sciatic nerve-anterior tibialis preparation, cumulative dose-response study and the estimation of recovery profiles from the twitch depression of about 95 % under pentobarbital, isoflurane or enflurane anesthesia was done. The ED50, ED95 and the recovery profiles were compared. RESULTS: The ED50 and ED95 under isoflurane (24.5 & 37.3) and enflurane (20.6 & 32.1) were significantly lower than those under pentobarbital anesthesia(28.4 & 42.9 ug/kg, respectively) without preadministrated SCh. The effective doses of MVC with preadministrated SCh had the same manner. The recovery profiles under enflurane anesthesia were significantly slower than those under pentobarbital anesthesia. The higher the recovered twitch height under enflurane anesthesia, the slower the recovery speed. CONCLUSION: The potency of MVC and recovery profiles under inhalation anesthetics are greater than those under pentobarbital. However, preadministrated SCh causes no significant difference in its potency or recovery.
Anesthesia ; Anesthetics ; Anesthetics, Inhalation ; Animals ; Cats* ; Depression ; Enflurane* ; Isoflurane* ; Neuromuscular Blockade* ; Pentobarbital ; Pharmacology ; Succinylcholine*

OBJECTIVETo study the effects of inhaled anesthetics on human sperm motility in vitro.

METHODSSperm samples were obtained from 20 healthy men by masturbation and prepared by the swim-up technique. The effects of isoflurane and sevoflurane at the clinical concentration (1.4%-5.6%) and high concentration (5.6%-84%) on human sperm motility in vitro were observed at 25 degrees C by the computer-assisted sperm analysis (CASA).

RESULTSThe sperm vitality and motility were significantly increased on 0.5-4 h exposure to isoflurane at the clinical concentration and decreased gradually at high concentration (42%-84%). The effect of isoflurane on human sperm motility and vitality at the clinical concentration was reversible when the anesthetic withdrawn. Sevoflurane had no effects on human sperm motility and vitality at either the clinical or high concentration.

CONCLUSIONIsoflurane has a reversible increasing effect at the clinical concentration and a significant decreasing effect at the high concentration on the motility and vitality of human sperm, while sevoflurane does not affect human sperm motility and vitality at either concentration.

Adult ; Anesthetics, Inhalation ; pharmacology ; Humans ; Isoflurane ; pharmacology ; Male ; Methyl Ethers ; pharmacology ; Sperm Motility ; drug effects ; Spermatozoa ; cytology ; drug effects ; physiology

Anesthetics, Inhalation ; pharmacology ; Child ; Electrocardiography ; Heart Rate ; drug effects ; Humans ; Isoflurane ; analogs & derivatives ; pharmacology ; Methyl Ethers ; pharmacology

OBJECTIVETo observe the effect of electro-acupuncture (EA) on auto regressive with exogenous input model (ARX-model) auditory evoked index (AAI) in patients anesthetized with different anesthetics.

METHODSForty-eight adult patients undergoing scheduled surgical operation were enrolled and divided into two groups (24 in each group) according to the anesthetics applied, Group A was anesthetized with propofol sedation and Group B with Isoflurane-epidural anesthesia. Group A was subdivided into three groups of low, middle and high concentration of target effect-site of 1.0 microg/ml, 1.5 microg/ml and 2.0 microg/ml through target controlled infusion (TCI) and Group B into 3 subgroups of minimum alveolar effective concentration of isoflurane (0.4 MAC, 0.6 MAC and 0.8 MAC for B1, B2 and B3 subgroups) respectively, with 8 patients in every subgroup. EA on acupoints of Hegu (LI4) and Neiguan (P6) was applied on all the patients during anesthesia, and the change of AAI at various time points was recorded.

RESULTSIn the three subgroups of Group A, levels of AAI were significantly elevated in the first few minutes after EA, and significantly lowered 20 min after EA in subgroup A2. While in the subgroups of Group B, except the elevating in Group B1 1-2 min after EA, levels of AAI remained unchanged at other time points.

CONCLUSIONPain response could be reflected by AAI during EA. EA could enhance the sedative effect of propofol in middle concentration, but its effect on isoflurane epidural anesthesia is insignificant.

Acupuncture Points ; Adult ; Anesthesia, General ; Anesthetics ; pharmacology ; Anesthetics, Inhalation ; pharmacology ; Anesthetics, Intravenous ; pharmacology ; Conscious Sedation ; Electroacupuncture ; Evoked Potentials, Auditory ; drug effects ; Female ; Humans ; Isoflurane ; pharmacology ; Laparotomy ; Male ; Middle Aged ; Monitoring, Intraoperative ; Pain Measurement ; Propofol ; pharmacology

OBJECTIVETo search new clues to reveal the action mechanism of inhaled anesthetics.

METHODSThree kinds of Drosophila melanogaster were used as studied models: the wild type strain (H), the sevoflurane-sensitive strain (S), and the sevoflurane-resistant strain (R). Differential display reverse transcriptional-polymerase chain reaction method was performed to examine the differentially expressed fragments between Drosophila induced with and without sevoflurane. Rapid amplification of cDNA ends (RACE) method was used to clone the full length cDNA from positive differentially expressed fragments.

RESULTSThirty-one differentially expressed fragments were found between the two groups. Three fragments were identified as the positive differentially expressed fragments by Northern blot analysis. Two full-length cDNAs were cloned by RACE method, among which one was a 1.0 kb Drosophila calmodulin (CaM), located on Chr.2; the other was a 4.1 kb gene with unknown function (No.45), located on Chr.3.

CONCLUSIONThe two full-length cDNAs belong to the genes that related to anesthetic action pathway, which might participate in the regulation of cellular functions and signal transduction pathways. The two genes that we found should provide a novel way to study the mechanism of inhaled anesthetic action.

Anesthetics, Inhalation ; pharmacology ; Animals ; Cloning, Molecular ; DNA, Complementary ; Drosophila melanogaster ; drug effects ; genetics ; Gene Expression ; Methyl Ethers ; pharmacology ; Signal Transduction

BACKGROUNDVital capacity induction and tidal breathing induction are currently administered for inhalation induction of anesthesia with sevoflurane. The aim of this study was to compare them using sevoflurane with respect to induction time, complications of inhalation induction, and compound A production in adult patients.

METHODSFifty-one women with American Society of Anesthesiologists physical status I-II undergoing mammary gland tumorectomy were randomly assigned to receive either vital capacity induction or tidal breathing induction with 8% sevoflurane at 6 L/min followed by laryngeal mask airway insertion. Induction times, complications of inhalation induction, and vital signs were recorded. Inspired concentrations of compound A were assayed and sofnolime temperatures were monitored at one-minute intervals after sevoflurane administration.

RESULTSThe time to loss of eyelash reflex was significantly shorter with the vital capacity induction technique than with the tidal breathing induction technique ((43.8 ± 13.4) seconds vs. (70.8 ± 16.4) seconds, respectively; P < 0.01). Cardiovascular stability was similar in both groups. The incidence of complications was significantly less with the vital capacity induction technique than with the tidal breathing induction technique (7.7% vs. 32%, respectively; P < 0.01). However, the mean and maximum concentrations of compound A during induction were significantly higher in the vital capacity group than those in the tidal breathing group (P < 0.05); compound A concentration at the beginning of anesthesia maintenance was (40.73 ± 10.83) ppm in the vital capacity group and (29.45 ± 7.51) ppm in tidal breathing group (P = 0.019).

CONCLUSIONFor inhalation induction of anesthesia, the vital capacity induction was faster and produced fewer complications than that for tidal breathing induction, but increased compound A production in the circuit system.

Adult ; Anesthesia, Inhalation ; methods ; Anesthetics, Inhalation ; pharmacology ; Ethers ; metabolism ; Female ; Hemodynamics ; drug effects ; Humans ; Hydrocarbons, Fluorinated ; metabolism ; Methyl Ethers ; pharmacology ; Middle Aged ; Temperature ; Tidal Volume ; Vital Capacity

The term "burst-suppression" is used to describe the electroencephalogram (EEG) pattern characterized by theta or delta waves, at times intermixed with faster waves, and intervening periods of relative quiescence. Burst-suppression pattern can reflect the seriously suppressed brain activity under deep anesthesia. To investigate the relationship between burst-suppression features and anesthetic concentration, we adopted four straightforward indexes, i. e., burst-suppression ratio (BSR), burst frequency, burst amplitude and suppression amplitude, and used them to analyze the EEG recordings in ten isoflurane-anesthetized rats. It was found that all the four burst-suppression indexes changed along with anesthetic concentration, that BSR and burst amplitude increased with higher concentration of isoflurane while burst frequency and suppression amplitude decreased, and that BSR was the most sensitive and consistent measurement to indicate isoflurane concentration so it constituted a valuable tool for timely evaluation of burst-suppression feature under deep anesthesia. The result also showed that the composition of carrier gas (i. e. pure oxygen vs. mixed oxygen) did not influence the effect of anesthesia significantly; and the four indexes of burst-suppression features could keep relatively stable within 60 min under the isoflurane concentration of 2%. The present study provides quantitative information of burst-suppression features under different anesthetic depth and may help to develop a clinically satisfied system that could quantify the characteristics of EEG and rigorously evaluate the cerebral state of patients.
Anesthesia, Inhalation ; Anesthetics, Inhalation ; pharmacology ; Animals ; Brain ; metabolism ; Electroencephalography ; drug effects ; Isoflurane ; pharmacology ; Male ; Rats ; Rats, Wistar ; Signal Processing, Computer-Assisted

The formalin test is a model of injury-produced inflammatory pain. Anesthetics, in clinically relevant concentrations, affect neutrophils and immune suppression. This study was to determine whether halothane reliably inhibits inflammatory reaction and formalin induced pain behavior or does not. Rats were exposed to 100% oxygen (control) or halothane, respectively for 30 min and then 24 hr later five percent formalin test was assessed. The base values of the paw's diameter were obtained earlier, and then formalin induced edema was assessed by measuring diameters of the injected paws at 5 min, 1 hr, 4 hr and 24 hr after the injection. Nociceptive behavior was quantified by counting the number of times with the paw flinched at 5 min intervals for 60 min. The diameters of edema in the halothane group lessened more than those in the oxygen group at 1 and 24 hr in each following of the injection (p<0.05). The rats pre-administered with oxygen or halothane were similar appearances in nociceptive behaviors. It suggests that halothane anesthesia might inhibit slightly the inflammatory reaction with the formalin-induced edema but might not inhibit the formalin-induced pain behavior in the event of pre-administration halothane 24 hr earlier before the formalin test of rat.
Anesthetics, Inhalation/pharmacology ; Anesthetics, Inhalation/immunology* ; Animal ; Edema/immunology* ; Edema/chemically induced ; Formaldehyde/pharmacology ; Formaldehyde/immunology ; Halothane/pharmacology ; Halothane/immunology* ; Hindlimb/immunology ; Hindlimb/drug effects ; Male ; Rats ; Rats, Sprague-Dawley

The data obtained from present experiments demonstrated that among several inhalation anesthetics, ether was the most irritable, resulting in marked irregularity of respiratory movement, and halothane depressed respiratory rate more than the other. The pulse rate and blood pressure were decreased marked1y in ether and the halothane anesthesia. the rate of beat of the isolated atria was not greately altered after anesthesia with ether or trichlore-thylene, while it was reduced after chloroform or halothane inhalation. The response of isolated atria to exogeneous norepinephrine was most prominent in the atria isolated from halothane anesthetized rabbits. Myocardial catecholamine contents were reduced uniformly after anesthesia with each anesthetics and most significantly with the halothane inhalation. From the above results, it may be concluded that the increasing cardiac activity with general inhalation anesthetics is closely related to the quantitative changes of the endogenous myocardial catecholamine contents.
Anesthesia, Inhalation/adverse effects ; Anesthetics/*toxicity ; Animals ; Catecholamines/*metabolism ; Heart/*drug effects ; Myocardium/*metabolism ; Norepinephrine/*pharmacology ; Rabbits

Adenosine ; pharmacology ; Anesthetics, Inhalation ; pharmacology ; Arginine ; pharmacology ; Cardiac Surgical Procedures ; methods ; Heart Arrest, Induced ; Humans ; Ischemic Preconditioning, Myocardial ; Myocardial Reperfusion Injury ; prevention & control ; Nitric Oxide ; physiology