Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1997
The effects of halothane and isoflurane on the phosphoenergetic state of the liver during hemorrhagic shock in rats: an in vivo 31P nuclear magnetic resonance spectroscopic study.
We studied the effects of halothane versus isoflurane on the phosphoenergetic state and intracellular pH (pHi) of the rat liver using in vivo 31P nuclear magnetic resonance (NMR) spectroscopy during and after hemorrhagic shock. Seventeen rats were anesthetized with 1 minimum alveolar anesthetic concentration of halothane or isoflurane. The mean arterial blood pressure was reduced to 40 mm Hg and maintained at this level for 45 min by withdrawing blood from the common carotid artery. ⋯ Intracellular acidosis was more severe in the halothane group. The recoveries of beta-ATP and P(i) were better in the isoflurane group. Halothane showed a more detrimental effect than isoflurane on the hepatic phosphoenergetic level during and after hemorrhagic shock.
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Anesthesia and analgesia · Aug 1997
Biography Historical ArticleAnesthesia & Analgesia: seventy-five years of publication.
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Anesthesia and analgesia · Aug 1997
The effects of sevoflurane on population spikes in CA1 and dentate gyrus of the rat hippocampus in vitro.
We studied the effects of sevoflurane on population spikes (PSs) in two synaptic pathways in rat hippocampal slices. Stimulating electrodes were placed on Schaffer collateral fibers or perforant path to activate inputs to CA1 pyramidal neurons or dentate gyrus (DG) neurons, respectively. Extracellular glass microelectrodes were used to record PSs. The paired-pulse stimulus was used to induce the paired-pulse facilitation (PPF). Sevoflurane (0.4-5.0 vol%) significantly decreased the amplitudes of PSs of CA1 and DG in a dose-dependent and reversible manner (25% effective dose values were 4.1 and 0.9 vol%, respectively). The stimulus-response relationships for PS amplitudes revealed that sevoflurane increased the threshold for PS generation in CA1 and DG. Sevoflurane (2.0 vol%) significantly enhanced PPF from 127% and 263% to 153% and 494% in CA1 and DG, respectively. The results imply that the effects of sevoflurane on PSs are greater in DG than in CA1 neurons, that sevoflurane enhances the PPF in both CA1 and DG, and that the actions of sevoflurane are not similar to those of other volatile or intravenous anesthetics previously reported in hippocampal preparations. ⋯ The volatile anesthetic sevoflurane alters neural excitability of individual pathways in the hippocampus in a manner different from other general anesthetics. The results are consistent with a site-specific mechanism of action for general anesthesia.