| Author/Editor | Bobrowska-Haegerstrand, Malgorzata; Kralj-Iglič, Veronika; Iglič, Aleš; Bialkowska, Katarzyna; Isomaa, Boris; Haegerstrand, Henry | |
| Title | Torocyte membrane endovesicles induced by octaethyleneglycol dodecylether in human erythrocytes | |
| Type | članek | |
| Source | Biophys J | |
| Vol. and No. | Letnik 77 | |
| Publication year | 1999 | |
| Volume | str. 3356-62 | |
| Language | eng | |
| Abstract | Endovesicles induced in human eryhrocytes 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 micro m. 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 provess in which and initially 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 from membrane inclusions with the effective sjape of an inverted truncated cone. If the interation 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 insluions and the membrane on the stability of the torocyte endovesicles are also indicated. | |
| Descriptors | ERYTHROCYTES ERYTHROCYTE MEMBRANE ETHYLENE GLYCOLS MICROSCOPY, CONFOCAL MICROSCOPY, ELECTRON FLUORESCENT DYES ISOTHIOCYANATES DEXTRANS |