help button home button Biophys. J.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bobrowska-Hägerstrand, M.
Right arrow Articles by Hägerstrand, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Bobrowska-Hägerstrand, M.
Right arrow Articles by Hägerstrand, H.

Biophys J, December 1999, p. 3356-3362, Vol. 77, No. 6

Torocyte Membrane Endovesicles Induced by Octaethyleneglycol Dodecylether in Human Erythrocytes

Malgorzata Bobrowska-Hägerstrand,* Veronika Kralj-Iglic,# Ales Iglic,§ Katarzyna Bialkowska, Boris Isomaa,* and Henry Hägerstrand*

 *Department of Biology, Åbo Akademi University, FIN-20520, Åbo/Turku, Finland;  #Institute of Biophysics, Medical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia;  §Laboratory of Applied Physics, Faculty of Electrical Engineering, SI-1000 Ljubljana, Slovenia; and  Institute of Biochemistry, University of Wroclaw, PL-51148 Wroclaw, Poland

Endovesicles induced in human erythrocytes by octaethyleneglycol dodecylether (C12E8) were studied by confocal laser scanning microscopy, using fluorescein isothiocyanate dextran as a nonspecific fluid marker. The endovesicles appeared to consist mainly of a ring-formed toroidal part joined with a central flat membrane segment. The torocyte contour length was several µm. There was usually one torocyte endovesicle per cell. The endovesicles seemed to be located near the cell surface. In sections of C12E8-treated erythrocytes transmission electron microscopy revealed the frequent occurrence of flat membrane structures with a bulby periphery, which apparently are cross sections of torocyte endovesicles. The possible physical mechanisms leading to the observed torocyte endovesicle shape are discussed. The torocyte endovesicles seem to be formed in a process in which an initially stomatocytic invagination loses volume while maintaining a large surface area. Because intercalation of C12E8 in the erythrocyte membrane induces inward membrane bending (stomatocytosis) we assume that C12E8 is preferentially located in the inner lipid layer of the erythrocyte membrane, i.e., in the outer lipid layer of the endovesicle membrane. It is suggested that local disturbances of the lipid molecules in the vicinity of the C12E8 molecules in the outer lipid layer of the endovesicle membrane form membrane inclusions with the effective shape of an inverted truncated cone. If the interaction between the inclusion and the membrane is weak, the membrane of such an endovesicle can be characterized by its negative spontaneous curvature, which may lead to a torocyte endovesicle shape with a small relative volume. Effects of a possible strong interaction between the C12E8-induced membrane inclusions and the membrane on the stability of the torocyte endovesicles are also indicated.

Biophys J, December 1999, p. 3356-3362, Vol. 77, No. 6
© 1999 by the Biophysical Society   0006-3495/99/12/3356/07  $2.00




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1999 by the Biophysical Society.