The formation of pentane and anaerobic metabolites of halothane (2-chloro-1,1,1-trifluoroethane and 2-chloro-1,1-difluoroethylene) in a mixture of guinea pig liver microsomes and halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) in the presence of NADPH was studied by gas chromatography. Under anaerobic conditions, pentane was formed without halothane and was inhibited by oxygen tension. This ...

The rat diaphragm was used as an in vitro model for studies of contractures synergistically-induced by halothane and suxamethonium. The effects of three agents reported to inhibit phospholipase A2 activity (quinacrine, spermine and indomethacin), tubocurarine and dantrolene were examined on these contractures. Contractures induced by 1% halothane (0.26 +/- 0.02 g) (mean +/- SEM) were increased ...

The effects of halothane and diethyl ether on the regenerating liver following 70 per cent hepatectomy were studied in Fisher/344 (F) rats. Our aim was to discover whether halothane administered repeatedly and over prolonged periods could influence the liver regenerative process or hepatocyte function. We also wished to know if the effects of halothane differed from those of diethyl ether. We f...

BACKGROUND Halothane is made and used as a racemate (an equimolar mixture of R- and S- enantiomers). This study was initiated to determine whether there were demonstrable enantiomeric differences in the whole-body pharmacokinetics of halothane that might have significance for studies in which racemate is used. METHODS Adult male Wistar rats were exposed to halothane vaporized in the atmospher...

Left ventricular and regional vascular effects of halothane were assessed in dogs and primates in which coronary, mesenteric, renal, and iliac blood flows, arterial blood pressure, left ventricular diameter and pressure, dD/dt (i.e., the velocity of myocardial fiber shortening), and dP/dt were continuously measured in the control resting state, while the conscious animals were breathing O2, and...

BACKGROUND Although in vitro studies have identified numerous possible targets, the molecules that mediate the in vivo effects of volatile anesthetics remain largely unknown. The mammalian ryanodine receptor (Ryr) is a known halothane target, and the authors hypothesized that it has a central role in anesthesia. METHODS Gene function of the Drosophila Ryr (dRyr) was manipulated in the whole b...

Malignant hyperthermia (MH) susceptibility is a genetic disorder of skeletal muscle associated with mutations in the ryanodine receptor isoform 1 (RyR1) of sarcoplasmic reticulum (SR). In MH-susceptible skeletal fibers, RyR1-mediated Ca(2+) release is highly sensitive to activation by the volatile anesthetic halothane. Indeed, studies with isolated RyR1 channels (using simple Cs(+) solutions) f...

Halothane (2-bromo-2-chloro-1,1,1-trifluoro-ethane) is an inhaled anesthetic that induces severe, idiosyncratic liver injury, i.e., "halothane hepatitis," in approximately 1 in 20,000 human patients. We used known human risk factors (female sex, adult age, and genetics) as well as probable risk factors (fasting and inflammatory stress) to develop a murine model with characteristics of human hal...

The polarographic reduction of halothane on silver cathodes was studied. Silver catalyses the reduction of halothane: two electrons are exchanged in the reduction process. Experiments using a rotating disc electrode showed a linear relationship between observed current and halothane concentration. A Silastic membrane-covered polarographic electrode was constructed using a silver cathode which g...

The effect of halothane or nitrous oxide or both, on division of cultured, murine bone-marrow cells was investigated. Halothane caused a dose-dependent depression of growth rate ranging from a minimal effect at 0.5% to almost total inhibition at 2.0%. Nitrous oxide 75% had an effect similar to 0.5% halothane and the combination of 0.75% halothane with 75% nitrous oxide produced results little d...