Author/Editor		Kuzman, Drago
Title		Merjenje elastičnih lastnosti membrane človeškega eritrocita z reološko metodo
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2003
Volume		str. 82
Language		slo
Abstract		The effect of the red blood cell (RBC) membrane mechanical properties on cell deformability is studied, where deformability describes the ability of the cell to change its shape in response to a deforming force. Previous studies indicated that the elastic properties of the membrane skeleton part, like shear and area expansivity, have a crucial impact on RBC deformability. In our analysis we assume that the local and non-local bending of the membrane lipid bilayer part also contribute to RBC deformability, where non-local bending depends on the bilayer leaflets equilibrium area difference (deltaA0). Surface area of the membrane is considered to be constant due to a large area expansivity of the lipid bilayer. The contributions to the RBC deformability of the other membrane elastic properties like bending of the skeleton and shear of the lipid bilayer are negligible and thus they are not considered into the analysis. The effect of the non-local bending energy to the RBC deformability is studied in a way that dependence of the RBC deformability on DeltaA0 is analysed. Experimentally, deltaA0 is modified and consequent discocyte-echinocyte shape transition obtained by the introducing of the amphiphatic agent sodium salicilate into cell suspension and by the high pressure aspiration into a narrow pipette. The echinocyte deformability is examined by rheological method and by the wide micropipette aspiration test. Results of the experiments indicate that RBC deformability of echinocyte is reduced and they are further analysed by the theoretical model considering a work needed for cell deformation that is equal to the increased membrane elastic energy. RBC deformation is thus described by the minimization of the corresponding thermodynamical potential. The cell shape is approximated by the parametric model. (Abstract truncated at 2000 characters).
Descriptors		ERYTHROCYTE MEMBRANE ERYTHROCYTE DEFORMABILITY RHEOLOGY ELASTICITY VISCOSITY