Macrorheological determinants,red cell membrane dynamic properties and erythrocyte Ca 2+ content (total and cytosollc) in VAD subjects with and without NIDDM

In 31 VAD subjects (mean age 66.9 ± 7.0 years) and in 20 VAD subjects with NIDDM (mean age 67.6 ± 7.2 years), we evaluated whole-blood filtration (VBC - according to the Reid method), mean erythrocyte aggregation (MEA - employing the aggregometer MA1 of Myrenne), erythrocyte membrane fluidity (marking intact red blood cells with 10-[1-pyrene] decanoic acid), red cell membrane protein lateral mobility (marking intact red blood cells with pyrene-3-maleimide), total red cell calcium content (using an atomic absorption spectrophotometer) and cytosolic red cell Ca²⁺ content (employing Fura 2-AM), and the relationships between them. In both groups, compared to controls, we observed a decrease of VBC, an increase of MEA, a decrease of the erythrocyte membrane fluidity and of the red cell membrane protein lateral mobility. As regards the red cell calcium content, we observed that, in VAD subjects with and without NIDDM, the total red cell calcium content is not different from controls, while only in VAD subjects with NIDDM, in comparison with normal controls, an increase in cytosolic red cell Ca²⁺ content is present. In normals and in VAD subjects with and without NIDDM, VBC and MEA are not related to the parameters reflecting the membrane dynamic properties nor to the red cell calcium content.