The factors affecting red blood cell aggregation kinetics

It has been reported that electrical properties of red cell suspensions also change during aggregation. The electrical properties of blood plasma and blood cells differ from each other. Several groups suggested that monitoring electrical properties of red cell suspensions during aggregation can provide information about the time course of aggregation, in a similar way to the photometric methods. In recent years, erythrocyte aggregation and aggregation time constant is thought to vary depending on the geometry. But there is not enough information about the kinetics of aggregation of small diameter capillaries. The aim of the study is the investigation of the alterations depending on the diameter in glass capillaries with different diameters in erythrocyte aggregation kinetics. Electrical properties of red blood cell (RBC) suspensions were recorded in a horizontal glass capillary, during and after the stoppage of flow induced by a syringe pump. Two stainless steel cylinders were fitted on both ends of the capillary serving as electrodes for electrical measurements. These electrodes were connected to a LCR meter for the measurement of electrical series capacitance (C). In this study, we evaluate the time period of erytrocyte agregation of glass capillary tubes with a diameter of between 80-800 micrometers. For this purpose, a flow was provided of various properties of erythrocyte suspensions through glass capillary tubes and the process of aggregation reflect the known properties of suspensions were monitored during the flow and after the current flow was stopped. The results of the current study also confirm of time-course related parameters influenced by geometry of the capillaries used for RBC aggregation measurements. The decreased diameters of glass capillaries resulted in significant and progressive changes of all kinetics of aggregation parameters as measured by the six glass capillaries. Especially, parameters reflecting the time course of RBC aggregation as determined between 80 and 800 µm were affected by the diameter of capillaries. The measurement of the electrical properties of the erythrocyte suspensions in glass capillary tubes with a small diameter can help to determine the erythrocyte aggregation kinetics in these the capillaries.