Effect of temperature dependent changes in mechanical stability of red cell aggregates on relative apparent whole blood viscosity

Article type: Research Article

Authors: Neumann, F.-J.^{; *} | Schmid-Schönbein, H. | Malotta, H.

Affiliations: Abt. Physiologie, RWTH Aachen, Pauwelsstr., D-5100 Aachen, F. R. Germany

Note: [*] Present address: Med. Univ.-Klinik Heidelberg, Abt. III (Kardiologie), Bergheimerstr. 58, D-6900 Heidelberg, F.R. Germany.

Note: [] Accepted by: Editor P. Gaehtgens

Abstract: As the temperature dependence of relative apparent whole blood viscosity ηrel is still controversial, the relation between the temperature dependence of red cell aggregation (RCA) and that of ηrel was examined in normal donors and in patients with venous ulcers of the leg. Apparent whole blood viscosity was measured in the DEER-rheometer (0.01Pa < τ < 2.9Pa) at 10°C, 20°C, 30°C and 37°C. The instrument was calibrated for each temperature to correct for changes in viscometer geometry. Simultaneously the minimal shear stress τTmin to keep RCA dispersed was determined by photometric aggregometry. ηrel was found to increase with decreasing temperature. By basing the relative cold induced increase in ηrel on the state of RCA as defined by the ratio of τ/τTmin the relation between both features is verified: With increaslng RCA the cold induced increase in ηrel is progressively enhanced.

Keywords: viscosity, red cell aggregation, temperature, erythrocyte

DOI: 10.3233/BIR-1987-24504

Journal: Biorheology, vol. 24, no. 5, pp. 463-472, 1987