Rheology of human blood and hyperlipemia

Abstract

By means of an electromagnetic coaxial cylinder viscometer, the blood from two hyperlipemic patients was studied near and at zero shear rate. The basic data: shear stress versus shear rate, were transformed to the respective square roots and plotted against each other. The resulting plots are linear, clearly defining at zero shear rate the yield shear stress and showing obedience to the Casson equation. The principal feature discovered from these data is that a) the yield shear stress reaches a maximum around 3 hr after ingestion of a fatty meal, this maximum being substantially greater than that of blood from the fasting subject, and b) the triglyceride concentration continues to rise to a maximum around 6 hr after ingestion, by which time the yield shear stress is approaching the normal value. A second feature, based on only one of the two subjects, is that the yield shear stress increases markedly as temperature of the blood decreases. Some comments are offered on the possible physiological relevance of the data and possible biophysical interpretations. low shear rheology; yield shear stress of lipemic blood; blood rheology-temperature relation; blood triglyceride concentration and yield shear stress Submitted on August 9, 1963