Simultaneous Measurements of K+ and Calcein Release from Liposomes and the Determination of Pore Size Formed in a Membrane

• 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

Abstract

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.

Journal

• Analytical Sciences

  Analytical Sciences 23 (5), 517-522, 2007

  The Japan Society for Analytical Chemistry

Keywords

• Analytical Chemistry

Details

• CRID: 1390001204258472960
• NII Article ID: 120002309901
• NII Article ID: 130004441439
• NII Book ID: AA10500785
• DOI: 10.2116/analsci.23.517
• ISSN: 13482246
• ISSN: 09106340
• NDL BIB ID: 8784876
• Web Site: https://ousar.lib.okayama-u.ac.jp/33008
• Web Site: http://id.ndl.go.jp/bib/8784876
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I8784876
• Web Site: https://link.springer.com/content/pdf/10.2116/analsci.23.517.pdf
• Web Site: https://link.springer.com/article/10.2116/analsci.23.517/fulltext.html
• Web Site: http://www.jstage.jst.go.jp/article/analsci/23/5/23_5_517/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed