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Effects of barbiturates and ethanol on the physical properties of brain membranes.
J Pharmacol Exp Ther. 1982 Nov; 223(2):424-31.JP

Abstract

Synaptic plasma membranes (SPM) and myelin were prepared from mouse brain and their physical properties evaluated by fluorescence probes. 1,6,-Diphenyl-1,3,5-hexatriene (DPH) was used as a probe of the membrane core and endogenous tryptophan as a probe of membrane proteins. In vitro addition of pentobarbital or ethanol decreased the fluorescence polarization of DPH in SPM. These decreases were not due to changes in fluorescence lifetime and indicate that both drugs increased the rotation mobility of the probe in the membrane core. This action was shared by other barbiturates and their potencies were correlated with their lipid solubility. In contrast to the effect on SPM, pentobarbital increased the fluorescence polarization of DPH in SPM phospholipids but had little effect on the fluorescence polarization of DPH in a total lipid extract from SPM. Pentobarbital did not affect fluorescence polarization of DPH in myelin. Analysis of the temperature dependence of pentobarbital effects indicated that the initial rigidity of the membranes was one factor determining whether the drug decreased, increased or did not change the membrane fluidity. Pentobarbital decreased the fluorescence intensity of SPM tryptophan, but did not affect the fluorescence of free tryptophan. Ethanol did not alter tryptophan fluorescence. Thus, pentobarbital, but not ethanol, produced a detectable perturbation of synaptic proteins. These results indicate that both pentobarbital and ethanol fluidized the hydrophobic core of the membrane, but pentobarbital differed from ethanol in its action on very fluid lipid domains and on membrane proteins.

Authors

No affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

7131297

Citation

Harris, R A., and F Schroeder. "Effects of Barbiturates and Ethanol On the Physical Properties of Brain Membranes." The Journal of Pharmacology and Experimental Therapeutics, vol. 223, no. 2, 1982, pp. 424-31.
Harris RA, Schroeder F. Effects of barbiturates and ethanol on the physical properties of brain membranes. J Pharmacol Exp Ther. 1982;223(2):424-31.
Harris, R. A., & Schroeder, F. (1982). Effects of barbiturates and ethanol on the physical properties of brain membranes. The Journal of Pharmacology and Experimental Therapeutics, 223(2), 424-31.
Harris RA, Schroeder F. Effects of Barbiturates and Ethanol On the Physical Properties of Brain Membranes. J Pharmacol Exp Ther. 1982;223(2):424-31. PubMed PMID: 7131297.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effects of barbiturates and ethanol on the physical properties of brain membranes. AU - Harris,R A, AU - Schroeder,F, PY - 1982/11/1/pubmed PY - 1982/11/1/medline PY - 1982/11/1/entrez SP - 424 EP - 31 JF - The Journal of pharmacology and experimental therapeutics JO - J Pharmacol Exp Ther VL - 223 IS - 2 N2 - Synaptic plasma membranes (SPM) and myelin were prepared from mouse brain and their physical properties evaluated by fluorescence probes. 1,6,-Diphenyl-1,3,5-hexatriene (DPH) was used as a probe of the membrane core and endogenous tryptophan as a probe of membrane proteins. In vitro addition of pentobarbital or ethanol decreased the fluorescence polarization of DPH in SPM. These decreases were not due to changes in fluorescence lifetime and indicate that both drugs increased the rotation mobility of the probe in the membrane core. This action was shared by other barbiturates and their potencies were correlated with their lipid solubility. In contrast to the effect on SPM, pentobarbital increased the fluorescence polarization of DPH in SPM phospholipids but had little effect on the fluorescence polarization of DPH in a total lipid extract from SPM. Pentobarbital did not affect fluorescence polarization of DPH in myelin. Analysis of the temperature dependence of pentobarbital effects indicated that the initial rigidity of the membranes was one factor determining whether the drug decreased, increased or did not change the membrane fluidity. Pentobarbital decreased the fluorescence intensity of SPM tryptophan, but did not affect the fluorescence of free tryptophan. Ethanol did not alter tryptophan fluorescence. Thus, pentobarbital, but not ethanol, produced a detectable perturbation of synaptic proteins. These results indicate that both pentobarbital and ethanol fluidized the hydrophobic core of the membrane, but pentobarbital differed from ethanol in its action on very fluid lipid domains and on membrane proteins. SN - 0022-3565 UR - https://www.unboundmedicine.com/medline/citation/7131297/Effects_of_barbiturates_and_ethanol_on_the_physical_properties_of_brain_membranes_ L2 - https://jpet.aspetjournals.org/cgi/pmidlookup?view=long&pmid=7131297 DB - PRIME DP - Unbound Medicine ER -