Effect of Ethanol and Acetaldehyde on Membrane-Bound Enzymes in Rat Brain
The acute effects of ethanol on the nervous system are thought to be associated with disturbance of neural membrane function. In the present study the effects of ethanol, its immediate metabolite, acetyldehyde, and tertiary butanol which is not further metabolized to an aldehyde, on selected membrane-bound enzymes were examined in vitro in rat brain. The enzymes included acetylcholinesterase, succinate dehydrogenase, Na+K+-ATPase and cytochrome c oxidase. At concentrations ranging from 0.07 – 2% w/v (15 – 435 mM) ethanol did not produce significant inhibition of any of the enzymes tested. On the other hand acetaldehyde at concentrations ranging from 0.01 – 0.5% w/v (2 – 114 mM) showed marked inhibition of all the abovementioned enzymes except acetylcholinesterase. The responses of the various enzymes to tertiary butanol were intermediate between those obtained with ethanol and acetaldehyde. Further studies are in progress to evaluate the significance of these findings to the understanding of alcohol intoxication, tolerance and dependence in man.
KeywordsSucrose Iodine Aldehyde Serotonin Fractionation
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- Chen, P.S. Jr., Toribara, T.Y., and Warner H., 1956, Microdetermination of phosphorus., Anal. Chem., 28: 1756.Google Scholar
- Chin, J.H. and Goldstein, D.B., 1977, Effects of low concentrations of ethanol on the fluidity of spin-labelled erythrocyte and braine membranes, Molec. Pharmacol., 13: 435.Google Scholar
- Duncan, H.M., and Mackler, B., 1966. Electron transport systems of yeast, J. Biol. Chem., 241: 1694.Google Scholar
- Ellman, G.L., Courtney, K.D., Andres, J. and Featherstone, R.M., 1961, A new and rapid calorimetric determination of acetylcholinesterase activity, Biochem. Pharmacol., 7: 88Google Scholar
- Erwin, V.G., Kim, J. and Anderson, A.D., 1975, Effects of aldehydes on sodium plus potassium ion-stimulated adenosine triphosphatase of mouse brain, Biochem. Pharmacol., 24: 2089.Google Scholar
- Gaines, K.C., Salhany, a.m., Tuna:, D.J., and Sorrell, M.G., 1977, Reaction of acetaldehyde with human erythrocyte membrane proteins, Feb. Letters, 75: 115.Google Scholar
- Goldstein, D.B., and Israel, Y., 1972. Effects of ethanol on mouse braine Na/K-activated ATPase, Life Sci., 11: 957.Google Scholar
- Hartree, E.F., 1972, Determination of protein, Anal. Biochem., 48: 422.Google Scholar
- Jones, D.H., and Mattis, A.I., 1974, Isolation of synaptic plasma membrane from brain by combined flotation-sedimentation density gradient centrifugation, Biochem. Biophys. Acta., 356: 276.Google Scholar
- porteus, J.W., and Clarke B., 1965, The isolation and characterisation of subcellular components of the epithelial cells of rabbit small intestine, Biochem. J., 96: 159.Google Scholar
- Wallgren, H., 1960, Relative intoxicating effects on rats of ethyl, propyl and butyl alcohols, Acta Pharmacol. Toxicol (kbh)., 16: 217.Google Scholar
- Wallgren, H., and Virtanen, P., 1978, Membrane effects of alcohol in the nervous system, In: “Proceedings of the European Society for Neurochemistry”, V. Neuhoff, ed., Verlag Chemie Weinheim, N.Y.Google Scholar