Physical properties of red cells as related to effects in vivo. I. Increased rigidity of erythrocytes as measured by viscosity of cells altered by chemical fixation, sickling and hypertonicity.

A SERIES OF STUDIES is reported on changes in physical properties of red cells that indicate abnormalities in their rigidity or deformability. Increased rigidity is a term used to describe changes in red cells leading to increased viscosity of flow, a shift to more Newtonian type of flow and lack of deformability as measured by packing under centrifugal force or by diminished flow through microfilters. Alterations in these physical properties will be related to changes in morphology, hemoglobin, stroma and to possible effects on the microcirculation and increased blood destruction. In this first report, the rigidity of unmanipulated cells is compared to the rigidity of cells following fixation with glutaraldehyde or formaldehyde, sickling, hypertonic shrinkage and combined sickling and shrinkage. In a second report’ thermal treatment of red cells or products of hemolysis is related