The effect of halothane on renal cortical blood flow (RCBF) has been investigated using the krypton 85 clearance technique, in seven dogs at normal arterial pressure, and in eight dogs at pressures of 100 mm Hg produced by bleeding. Halothane 0.5 per cent caused small and variable changes in RCBF in the normotensive animals. In the hypotensive animals, halothane 0.5 per cent caused a marked ris...

In 14 mongrel dogs wash-in and wash-out curves for halothane were obtained from measurements of arterial blood, mixed venous blood and end-tidal gas. From a certain point in the wash-in period the halothane concentration of arterial blood can be calculated from the halothane concentration in end-tidal gas and the blood-gas partition coefficient for halothane. Analysis of the curves shows that t...

Protein kinase C (PKC) is a key regulatory enzyme that has been implicated as a molecular target for the action of general anaesthetics. We have determined the effects of halothane on the translocation and down-regulation of conventional PKC (cPKC) by analysing the subcellular distribution of PKC activity, [3H]phorbol-12,13-dibutyrate ([3H]PDBu) binding and PKC immunoreactivity in intact rat ce...

Earlier studies have suggested that halothane may relax smooth muscle in part by opening adenosine triphosphate-sensitive potassium (KATP) channels. We tested this hypothesis in vitro by examining the interaction of halothane with glibenclamide, a KATP channel blocker, and YM934, a KATP channel opener, in strips of canine tracheal smooth muscles mounted in an organ bath system. To examine the s...

PURPOSE To determine whether the volatile anesthetic halothane protects against light-induced photoreceptor degeneration in the rodent retina. METHODS Albino mice and rats were anesthetized with halothane and exposed to high levels of white or blue light. Nonanesthetized animals served as controls. Retinal morphology was assessed by light microscopy, and apoptosis of photoreceptor cells was v...

The potential toxicity of halogenated anaesthetics on cellular immunity has been investigated on guineapig macrophages in gas phase by measuring the adenosine 5' triphosphate (ATP) concentration in the macrophages. A toxicity index (TI) was obtained by comparing the ATP concentration in vapour or gas-exposed macrophages with that of control cells. The TI for 5% halothane in air after 24 h was 3...

We selected nine normal subjects (8M, 1F; aged 25-43 yr) with brisk hypoxic ventilatory responses, and studied their ventilatory response to sustained isocapnic hypoxia (SaO2 82 (SEM 0.1) % for 25 min) in the presence and absence of 0.1% inspired halothane. Halothane had no significant effect on baseline ventilation or gas exchange. In the absence of halothane, ventilation increased initially f...

Halothane (1,1,1-trifluoro-2-bromo-2-chloroethane) is a safe, clinically useful inhalation anesthetic. Rare, unpredictable cases of liver necrosis have been reported following its use. Although the mechanism of this reaction in man is unknown the most plausible is biotransformation to reactive intermediates compounds. The oxidative metabolism of halothane appears to be benign. There is early ev...

The effect of halothane anaesthesia on the activity of the mitochondrial enzyme pyruvate dehydrogenase was studied in starved lactating rats. Extracts of freeze-clamped mammary gland and liver were assayed for pyruvate dehydrogenase activity. The fraction of the enzyme in the phosphorylated inactive form was increased greatly by starvation or by streptozotocin diabetes, and halothane anaesthesi...

Halothane and propofol enhance the activity of the -aminobutyric acid (GABA) system, which is one of the most important systems in the mechanism of anesthesia. To determine whether halothane and propofol enhance GABAergic responses by the same mechanism, we performed single-channel patch-clamp experiments with rat cortical neurons in primary culture. Each of the open-time and closed-time distri...