Utilize este identificador para referenciar este registo: http://hdl.handle.net/10451/20183
Título: Fluorescent probes DPH, TMA-DPH and C17-HC induce erythrocyte exovesiculation
Autor: Saldanha, C.
Santos, N. C.
Martins-Silva, J.
Palavras-chave: Erythocyte membranevesicle
Acetylcholinesterase
Membrane fluidity
Lipid microdomains
Cholesterol
Dynamic light scattering
Data: 2002
Editora: Springer
Citação: J. Membrane Biol. 190, 75-82 (2002)
Resumo: An experimental approach has been developed to study human erythrocyte vesiculation, using the fluorescent probes diphenylhexatriene (DPH), trimethylamino-diphenylhexatriene (TMA-DPH) and heptadecyl-hydroxycoumarin (C17-HC). Acetylcholinesterase (AChE) enzyme activity measurements confirmed the presence of exovesicles released from erythrocyte membranes labeled with DPH, TMA-DPH or C17-HC. The fluorescence intensity and anisotropy values obtained showed that the amphiphilic probes TMA-DPH and C17-HC are preferentially incorporated in the exovesicles (when compared with DPH). There is a significant decrease of the cholesterol content of the exovesicle suspensions with time, independently of the fluorescence probe used, reaching undetectable cholesterol levels for the samples incubated for 48 hr. The ratios between the concentration of cholesterol released in the exovesicles after 1 hr incubation with DPH, TMA-DPH or C17-HC and the probe concentration used in the incubation were 84.7, 3.82 and 0.074, respectively. The size of the released vesicles was evaluated by dynamic light scattering spectroscopy. Some hypotheses are proposed that could explain the resemblance and differences between the results obtained for erythrocytes labeled with each probe, considering the present knowledge of membrane vesiculation mechanisms, lipid microdomains (rafts), erythrocyte membrane phospholipid asymmetry and AChE inhibition by TMA-DPH and C17-HC. This work demonstrates that the fluorescent probes DPH, TMA-DPH and C17-HC induce rapid erythrocyte exovesiculation; their use can lead to new methodologies for the study of this still poorly understood mechanism.
Descrição: © 2002 Springer-Verlag New York Inc.
Peer review: yes
URI: http://hdl.handle.net/10451/20183
DOI: http://dx.doi.org/10.1007/s00232-002-1025-5
ISSN: 0022-2631
Versão do Editor: http://link.springer.com/journal/232
Aparece nas colecções:IMM - Artigos em Revistas Internacionais
FM-IB-Artigos em Revistas Internacionais

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