Influence of hypercholesterolemia on morphological and rheological characteristics of erythrocytes.

The changes in shape and rheological parameters of erythrocytes in cholesterol-fed rabbits (fed with normal diet plus 0.5% cholesterol for a duration of 1 year) and in vitro cholesterol enrichment of erythrocytes in cholesterol enriched plasma were studied. This process affects the shape of erythrocytes. In rabbits the actual shape change begins after 6 weeks of cholesterol feeding. The shape changes in rabbits and in vitro cholesterol-enrichment are similar. The extent of shape changes depends on the amount of cholesterol incorporated into the membrane. The rheological parameters such as blood viscosity, osmotic fragility and deformability are measured. The whole blood viscosity is increased and deformability decreased. The cells become osmotically more fragile in cholesterol-fed rabbits but are resistant to osmotic lysis in in vitro cholesterol enrichment. The altered lipid composition may be responsible for the observed changes in these parameters.