title: Filtrability investigations with red blood cell (RBC) suspensions: effects of different blood components and pentoxifylline on RBC flow rate.
abstract: RBC deformability provide an important and limitating factor in blood flow and microcirculatory perfusion. A relative great number of tests are available to estimate RBC deformability, e.g. filtration methods. We performed several tests with a filtration method (Nucleopore) whereby several basically different parameters have to be taken into consideration (driving pressure, volume of filtered suspension, number of filtered cells, flow rate and so on). We could show that RBC filtration will be influenced by the number of leucocytes and the plasma, as a great quantity of the pores will actually be plugged by the leucocytes and cell aggregation will occur due to plasma protein bridging. In order to assess RBC deformability by filtration tests, it is necessary to control all variables affecting the rheological behavior of red cells: washing and suspending in buffer, control of temperature, osmolarity and pH-values, quantification and calibration of the filter, calculation of relative flow rate (Vrel = Vsusp/Vsusp medium). Under these circumstances we tested the bloodrheological effect of pentoxifylline (Trental) on less deformable red cells. Red cell rigidification was obtained by lactacidosis or cellular ageing in buffer associated with loss in erythrocytic ATP content. A protective effect of pentoxifylline against red cell rigidification in the microfiltration test could be demonstrated.
mesh_terms: D000818:Animals; D001775:Blood Circulation / Q000187:drug effects; D001790:Blood Physiological Phenomena; D004285:Dogs; D004912:Erythrocytes / Q000502:physiology*; D006801:Humans; D010431:Pentoxifylline / Q000494:pharmacology*; D012212:Rheology; D013805:Theobromine / Q000031:analogs & derivatives*; D014462:Ultrafiltration
chemical_list: D013805:Theobromine; D010431:Pentoxifylline