Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 2751922

Inhalation anaesthetics decrease calcium content of cardiac sarcoplasmic reticulum.

M Katsuoka·S T Ohnishi
View original source ↗Export metadata ↓

Abstract

In a Langendorff perfused rat heart model, caffeine was shown to have a negative inotropic effect similar to that of inhalation anaesthetics. Both inhalation anaesthetics and caffeine decreased calcium content of left ventricular muscle as measured by atomic absorption spectroscopy. Halothane 2.8% decreased left ventricular pressure by 75.4 (SEM 4.4)% and decreased the calcium content by 30%. Enflurane 5.1% decreased the pressure by 72.4 (6.0)% and decreased calcium content by 31%. Both halothane and enflurane decreased the calcium content of sarcoplasmic reticulum (SR) as measured by caffeine-induced calcium release. There was a high degree of correlation between the negative inotropic effect of inhalation anaesthetics and the decrease in calcium content of the SR (r = 0.95 for halothane, r = 0.91 for enflurane). These data suggest that inhalation anaesthetics increase the calcium permeability of cardiac SR, thereby decreasing the calcium content of SR, resulting in the negative inotropic effect.

Explore related subjects

AnestheticsAnimalsCaffeineCalciumEnfluraneHalothaneHeartIn Vitro TechniquesMaleMyocardial ContractionMyocardiumPapillary MusclesRatsRats, Inbred StrainsSarcoplasmic ReticulumJournal ArticleResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Katsuoka, S T Ohnishi. 1989. Inhalation anaesthetics decrease calcium content of cardiac sarcoplasmic reticulum.. https://doi.org/10.1093/bja%2F62.6.669

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

General anaesthetics inhibit the responses induced by glutamate receptor agonists in the mouse cortex.

The effects of several general anaesthetics on the responses evoked by the excitatory amino acid agonists N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) were investigated in mouse cortical wedges placed in a two compartment bath and superfused with a nominally Mg(2+)-free Krebs solution. Chloroform (3-6 mM) and halothane (1-3 mM) preferentially antagonized AMPA responses; thiopental (0.1-0.4 mM), diethyl ether (10-30 mM) and isoflurane (1-3 mM) antagonized both AMPA or NMDA responses while ketamine antagonized NMDA responses in a highly selective way. The antagonism of the excitatory amino acid responses exerted by the anaesthetics was non competitive in nature. The inhibition of excitatory amino acid receptor function may be one of the mechanisms whereby general anaesthesia is produced.

Anesthetics↗
PubMed1992

Nature of alcohol and anesthetic action on cooperative membrane equilibria.

A generalized, colligative thermodynamic framework is used to treat the action of solutes on cooperative membrane equilibria. Configurational entropy, the randomness imparted by solutes through the partitioning or mixing process, is implicated as the energetic driving force for the action of anesthetics on cooperative membrane equilibria. The equilibria predicted to be most sensitive to solute action--in which the dilute solute causes a perturbation equivalent to a large change in temperature--are (1) low-enthalpy processes that coincide with (2) large partitioning differences between states. The model stresses that solutes do not act at a single site, but on both states in an equilibrium, and that the perturbation is determined by the difference in entropy. Evidence for the thermodynamic framework is obtained from the partitioning behavior of the general anesthetic 1-hexanol into a model lecithin (DMPC; 1,2-dimyristoyl-sn-glycero-3-phosphocholine) membrane as a function of temperature and alcohol concentration. The low-enthalpy equilibrium between the gel (L beta') and ripple states (P beta') (pretransition) is more sensitive to 1-hexanol than the high-enthalpy equilibrium between the ripple (P beta') and fluid bilayer states (L alpha) (main transition). The perturbations of both equilibria are accurately described by the colligative thermodynamic framework. The results suggest that alcohols and anesthetics act through entropy to upset the natural thermal balance that maintains native membrane architecture.

Anesthetics↗