ORIGIN OF INVAGINATIONS AND VESICLES IN LIPOSOMES UNDER THE ACTION OF ENDOCYTOSIS INDUCTORS, INCLUDING OXIDANTS

  • 1 January 1979
    • journal article
    • research article
    • Vol. 21  (9) , 1009-1015
Abstract
The action of various substances on the morphology of multilayer membranes made of lipids of egg yolk was studied. Electroneutral and anionic compounds scarce affected liposomes, whereas substances with pronounced basic properties, i.e., peroxidase, Hb, cytochrome c and RNAase, as well as lanthanium ions, induced the formation of invaginations, vesicles and aggregation of liposomes. Metals with variable valency: Cu2+, Cu4+, Ru6+, including lipid oxidants Fe3+ and UO22+, produced similar morphological changes more intensely and moreover destroyed liposomal membranes. The activator of lipid peroxidation, namely ascorbic acid, intensified while antioxidizers such as .alpha.-tocopherylacetate and ionol removed the action of Fe3+ on liposomes. A protective effect was displayed by Ca2+ and Mg2+ ions due to an increase in pH medium. Since many tested substances with basic properties stimulate endocytosis of cells, the processes of lipid peroxidation and electrostatic interactions are apparently part of an endocytosis mechanism which does not involve metabolic energy. Endocytosis may have arisen at the protocells stage in terms of evolutions.