Effects of calcium and A23187 on deformability and volume of human red blood cells.
Human red blood cells treated in vitro with Ca2+ plus A23187 in low K+ medium exhibited significantly decreased cell volume and deformability, the latter determined by ektacytometry. These effects of Ca2+ plus A23187 were prevented in the presence of high K+ medium. Increased K+ permeability mediated by increased intracellular Ca2+ (Gardos effect) was apparently responsible for decreased cell volume and deformability in low K+ medium. Although it is commonly accepted that Ca2+ accumulation and/or ATP depletion per se cause decreased red blood cell deformability, the present results demonstrate that acutely induced changes in red blood cell volume as promoted by Ca2+ are a more important determinant of red blood cell deformability.
D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D004907:Erythrocyte Deformability / Q000187:drug effects*; D004912:Erythrocytes / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D013314:Stress, Mechanical
D000001:Calcimycin; D002118:Calcium