Tamoxifen perturbs lipid bilayer order and permeability: comparison of DSC, fluorescence anisotropy, laurdan generalized polarization and carboxyfluorescein leakage studies.
Biophys Chem
; 90(2): 157-73, 2001 Apr 10.
Article
em En
| MEDLINE
| ID: mdl-11352274
The perturbation of the lipid bilayer structure by tamoxifen may contribute to its multiple mechanisms of anticancer action not related to estrogen receptors. This study evaluates the effect of tamoxifen on structural characteristics of model membranes using differential scanning calorimetry (DSC), fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-[4-[trimethylammonium)phenyl]-6-phenylhexa-1,3,5-triene (TMA-DPH), as well as 6-dodecanoyl-2-dimethylaminonaphthalene (Laurdan) generalized polarization. The comparative measurements in multilammelar vesicles (MLV) prepared from dipalmitoylphosphatidylcholine (DPPC) revealed that tamoxifen decreases the phase transition temperature (Tm) paralleled by a broadening of the phase transition profile. In large unilamellar vesicles (LUV) prepared from egg yolk phosphatidylcholine (EPC), tamoxifen increased the lipid bilayer order predominantly in the outer bilayer region. From membrane permeability measurements, we conclude that the tamoxifen-induced release of entrapped carboxyfluorescein (CF) results from a permanent bilayer disruption and the formation of transient holes in the lipid bilayer.
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Base de dados:
MEDLINE
Assunto principal:
Tamoxifeno
/
Bicamadas Lipídicas
/
2-Naftilamina
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Biophys Chem
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Alemanha