Modification of the erythrocyte membrane dielectric constant by alcohols.
J Membr Biol
; 104(1): 57-68, 1988 Aug.
Article
em En
| MEDLINE
| ID: mdl-3184178
Aliphatic alcohols are found to stimulate the transmembrane fluxes of a hydrophobic cation (tetraphenylarsonium, TPA) and anion (AN-12) 5-20 times in red blood cells. The results are analyzed using the Born-Parsegian equation (Parsegian, A., 1969, Nature (London) 221:844-846), together with the Clausius-Mossotti equation to calculate membrane dielectric energy barriers. Using established literature values of membrane thickness, native membrane dielectric constant, TPA ionic radius, and alcohol properties (partition coefficient, molar volume, dielectric constant), the TPA permeability data is predicted remarkably well by theory. If the radius of AN-12 is taken as 1.9 A, its permeability in the presence of butanol is also described by our analysis. Further, the theory quantitatively accounts for the data of Gutknecht and Tosteson (Gutknecht, J., Tosteson, D.C., 1970, J. Gen. Physiol. 55:359-374) covering alcohol-induced conductivity changes of 3 orders of magnitude in artificial bilayers. Other explanations including perturbations of membrane fluidity, surface charge, membrane thickness, and dipole potential are discussed. However, the large magnitude of the stimulation, the more pronounced effect on smaller ions, and the acceleration of both anions and cations suggest membrane dielectric constant change as the primary basis of alcohol effects.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Permeabilidade da Membrana Celular
/
Álcoois
/
Membrana Eritrocítica
/
Íons
Limite:
Humans
Idioma:
En
Revista:
J Membr Biol
Ano de publicação:
1988
Tipo de documento:
Article