Effect of temperature on the velocity of erythrocyte aggregation

Autoregulation of the Brain Temperature during Whole Body Hyperthermia

“…In 1987 Maeda et al [23] showed that at increase in temperature (in a range of 5 to 43 ∘ C) velocity of fibrinogeninduced RBC aggregation increases. Our data presented in Table 1 show that increase of temperature in hyperthermic chamber leads to multiple, statistically significant increase in the rats' RBC aggregation index, which, in contrast to other vertebrates, as already noted, normally probably is very low [24].…”

Optically clear biomicroviscometer with modular geometry using disposable PDMS chips

“…The RBCs naturally tend to cluster together and form structures that resemble coin stacks, called rouleaux [22], [23]. This process is one of the mechanisms that cause the viscosity of blood to increase as the shear rate decreases, because aggregation typically occurs under low shear rate.…”

“…The mechanisms which are believed to cause aggregation are based either on (1) the bridging of adjacent RBCs, or (2) the depletion of molecules between cells [23]. The "bridging" theories purport that macromolecules such as fibrinogen, that are attached to the surface of the RBCs, are able to contact molecules of their type on adjacent cells, and bridge under favourable conditions [22], [25]. If the forces acting to keep the cells apart are sufficiently high, e.g.…”

“…The temperature of the blood affects the rate of aggregation, with the speed depending on the temperature range [22], [27]. Maeda et al [22] found that, at a shear rate of 7.5 s -1 , the aggregation speed decreases when increasing the blood temperature from 5 °C to 20 °C, whereas the aggregation speed would increase as the temperature increased further, from about 20 °C to 43 °C; in other words, the rate of aggregation was minimum at approximately 20 °C. Singh et al [27] performed a study of the aggregation indices measured in blood and found similar results using a fully automatic aggregometer, which could apply shear rates up to 600 s -1 .…”

“…This trend of temperature-dependent aggregation has been explained to be the result of the combined effects of various phenomena that change with temperature: the frequency of cell collisions (which increases with temperature and promotes aggregation), fluid shear forces (which increase with temperature and counteracts aggregation), and the properties of macromolecules and RBCs, themselves [22]. The effect of temperature on the storage of the blood cells should also be considered when planning experiments.…”