The effect of ethanol on the physical properties of neuronal membranes.
Intramolecular excimer formation of 1,3-di(1-pyrenyl) propane(Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to evaluate the effect of ethanol on the rate and range of lateral and rotational mobilities of bulk bilayer structures of synaptosomal plasma membrane vesicles (SPMVs) from the bovine cerebral cortex. Ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMVs. Selective quenching of both DPH and Py-3-Py by trinitrophenyl groups was used to examine the range of transbilayer asymmetric rotational mobility and the rate and range of transbilayer asymmetric lateral mobility of SPMVs. Ethanol increased the rotational and lateral mobility of the outer monolayer more than of the inner one. Thus ethanol has a selective fluidizing effect within the transbilayer domains of the SPMVs. Radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py was used to examine both the effect of ethanol on annular lipid fluidity and protein distribution in the SPMVs. Ethanol increased annular lipid fluidity and also caused membrane proteins to cluster. These effects on neuronal membranes may be responsible for some, though not all, of the general anesthetic actions of ethanol.
Bae
Moon-Kyoung
MK
Department of Dental Pharmacology and Biophysics, College of Dentistry and Research Institute for Oral Biotechnology, Pusan National University, Busan, Korea.
Jeong
Dong-Keun
DK
Park
No-Soo
NS
Lee
Cheol-Ho
CH
Cho
Bong-Hye
BH
Jang
Hye-Ock
HO
Yun
Il
I
D000818:Animals; D002417:Cattle; D002462:Cell Membrane / Q000187:drug effects*; D002540:Cerebral Cortex / Q000166:cytology* / Q000187:drug effects; D004161:Diphenylhexatriene; D000431:Ethanol / Q000494:pharmacology*; D005456:Fluorescent Dyes; D005470:Fluorometry; D008051:Lipid Bilayers / Q000737:chemistry; D008560:Membrane Fluidity / Q000187:drug effects*; D008565:Membrane Proteins / Q000737:chemistry / Q000187:drug effects; D011721:Pyrenes / Q000737:chemistry; D013574:Synaptosomes / Q000187:drug effects*; D014302:Trinitrobenzenesulfonic Acid
D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008565:Membrane Proteins; D011721:Pyrenes; D004161:Diphenylhexatriene; D000431:Ethanol; C035116:1,3-di-(1-pyrenyl)propane; D014302:Trinitrobenzenesulfonic Acid