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ID 33008
フルテキストURL
著者
Katsu, Takashi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
Imamura, Tomonori Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
Komagoe, Keiko Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
Masuda, Kazufumi Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
Mizushima, Tohru Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University
抄録

The changes induced by biologically active substances in the permeability to K+ and calcein of liposomes composed of egg phosphatidylcholine and cholesterol were measured simultaneously in order to rapidly screen the sizes of pores formed in a membrane, using different sized markers. The substances examined in the present study were classified into three types based on differences in the rates at which K+ and calcein were released. The first type released only K+, and included gramicidin A. The second type predominantly released K+, preceding the release of calcein, and included amphotericin B and nystatin. The third type, including antimicrobial peptides, such as gramicidin S, alamethicin, and melittin, and several membrane-active drugs, like celecoxib (non-steroidal anti-inflammatory drug), 1-dodecylazacycloheptan-2-one (named azone; skin permeation enhancer), and chlorpromazine (tranquilizer), caused the release of K+ and calcein simultaneously. Thus, the sizes of pores formed in a liposomal membrane increased in the following order: types one, two, and three. We determined the size more precisely by conducting an osmotic protection experiment, measuring the release of calcein in the presence of osmotic protectants of different sizes. The radii of pores formed by the second type, amphotericin B and nystatin, were 0.36 - 0.46 nm, while the radii of pores formed by the third type were much larger, 0.63 - 0.67 nm or more. The permeability changes induced by substances of the third type are discussed in connection with a transient pore formed in a lipid packing mismatch taking place during the phase transition of dipalmitoylphosphatidylcholine liposomes.

備考
Published with permission from the copyright holder.
This is published in Analytical Sciences, 2007 Vol.23 Issue.5 pp.517-522
Publisher URL: http://dx.doi.org/10.2116/analsci.23.517
Direct access to Thomson Web of Science record
(C)2008 by The Japan Society for Analytical Chemistry
発行日
2007-05-10
出版物タイトル
Analytical Sciences
23巻
5号
開始ページ
517
終了ページ
522
資料タイプ
学術雑誌論文
言語
English
査読
有り
DOI
Web of Sience KeyUT
Submission Path
analytical_chemistry/43