Examination of a rheological profile for blood using micropore filters

Various techniques have been used to assess the now properties of blood and blood cells in a range of clinical situations, Filtration through microfil ters offers a single technique for measuring the now properties of all cell ular components of blood in one experiment but depends on an assumed abilit y to recognize cells that make up <10% of leucocytes. The remaining leucocy tes, labelled fast leucocytes, were previously presumed to be lymphocytes a nd granulocytes. This study confirmed the identities of these fast leucocyt es as those of lymphocytes and granulocytes in undiluted blood. The transit time for lymphocytes (1.2 s) and granulocytes (1.6 s) is close to that rec orded for fast leucocytes (1.7 s). The resistance of each type of blood cel l to now through 5 mu m filters was defined in this study as the product of the concentration of that cell in blood and its transit time through a por e in the filter. The total resistance to now of healthy blood through the f ilter is 4.46 x 10(7) s/ml and is attributed to plasma (2.7%), red cells (2 5.9%), fast leucocytes (25.3%) and slow leucocytes (46.1%). In a cohort of 21 men with peripheral arterial disease the total resistance was increased to 7.82x10(7) s/ml and attributed to plasma (1.5%), red cells (14.5%), fast leucocytes (21.0%) and slow leucocytes (63.0%). This analysis therefore pr ovides a single test for assessing the now properties of all the cellular c omponents of blood and plasma.