Stycholysin II, a cytolysin from the sea anemone Stichodactyla helianthus promotes higher hemolysis in aged red blood cells.
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.
Celedón
Gloria
G
Departamento de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Chile.
González
Gustavo
G
Barrientos
Daniela
D
Pino
Jose
J
Venegas
Fabiola
F
Lissi
Eduardo A
EA
Soto
Carmen
C
Martinez
Diana
D
Alvarez
Carlos
C
Lanio
María Eliana
ME
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*
D003064:Cnidarian Venoms; D052899:Pore Forming Cytotoxic Proteins; C404794:sticholysin II; D011188:Potassium