title: Stycholysin II, a cytolysin from the sea anemone Stichodactyla helianthus promotes higher hemolysis in aged red blood cells.
abstract: We have investigated the relationship between the status of red blood cells (RBCs) and their susceptibility to toxin sticholysin II (StII) hemolytic activity; we have evaluated this effect in different RBC ensembles, comprising young and old cells, and in cells partially damaged by their pre-exposition to a free radical source. Upon action of StII, young cell populations are less prone to hemolysis than the whole population, while old cell populations and peroxyl-oxidized red cells are lysed faster than the whole population. Cell K(+) content was higher in young cells and lower in both senescent cells and in peroxyl-damaged cells relative to whole cell population. The relevance of cell K(+) content in St II-induced lysis was shown when external Na(+) was partially replaced by K(+); under this condition, RBC lysed faster in the presence of St II but no difference was observed among young cells, whole cells population and peroxyl-damaged cells; only old cells lysed faster that the whole population, response that can be due to an enhanced St II-induced pore formation as supported by evaluation of St II irreversible binding to RBC. It is concluded that this factor and the amount of intracellular K(+) are the dominant parameters that modulate the resistance of RBC to St II-induced lysis.
authors.affiliation: Departamento de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile.
authors.forename: Gloria
authors.initials: G
authors.lastname: Celedón
authors.forename: Gustavo
authors.initials: G
authors.lastname: González
authors.forename: Daniela
authors.initials: D
authors.lastname: Barrientos
authors.forename: Jose
authors.initials: J
authors.lastname: Pino
authors.forename: Fabiola
authors.initials: F
authors.lastname: Venegas
authors.forename: Eduardo A
authors.initials: EA
authors.lastname: Lissi
authors.forename: Carmen
authors.initials: C
authors.lastname: Soto
authors.forename: Diana
authors.initials: D
authors.lastname: Martinez
authors.forename: Carlos
authors.initials: C
authors.lastname: Alvarez
authors.forename: María Eliana
authors.initials: ME
authors.lastname: Lanio
mesh_terms: D000818:Animals; D002469:Cell Separation; D003064:Cnidarian Venoms / Q000494:pharmacology*; D004905:Erythrocyte Aging; D004912:Erythrocytes / Q000187:drug effects*; D006461:Hemolysis / Q000187:drug effects*; D009996:Osmotic Fragility; D018384:Oxidative Stress; D052899:Pore Forming Cytotoxic Proteins / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D012615:Sea Anemones / Q000737:chemistry*
chemical_list: D003064:Cnidarian Venoms; D052899:Pore Forming Cytotoxic Proteins; C404794:sticholysin II; D011188:Potassium