血细胞压积对人体全血触变特性的影响

采用改良型Weissenberg 流变性测定仪,研究血细胞压积(HCT)对全血触变参数的影响,结果表明下列参数,即屈服应力、粘度的牛顿分量、粘度的非牛顿分量、表观粘度和结构参数平衡值随着血细胞压积的增加而作指数样增高,并得出经验公式表示这些参数与血细胞压积之间的关系。而另两个触变参数,即叠连解体成单个红细胞的动力速率常数和解体反应的阶数,与血细胞压和无依赖关系,这些结果与反应动力学理论是一致的。

EFFECT OF HEMATOCRIT ON THIXOTROPIC PROPERTIES OF WHOLE HUMAN BLOOD

Whole human blood exhibits the thixo-tropic properties at a low shear rate from0.1 to 10 sec~(-1). The canse of this shear rate-dependent and time-dependent behavior isthe progressive breakdown of rouleaux in-to individual red cells. The Huang's rheol-ogical equation described the kinetics ofrouleaux breakdown. This five-parameterequation was used successfully to representthe hysteresis loop and the torque-decaycurve of whole human blood. In this com-munication, we examined the effect of he-matocrit on each of the above-mentionedparameters using the modified Weissenbergrheogoniometer. The results showed thatthe following parameters would increasetheir values exponentially as the hemato-crit was increased: the yield stress, New-tonian contribution of viscosity, apparentviscosity, non-Newtonian contribution ofviscosity and the equilibrium value of thestructural parameter which indicates therelative amount of rouleaux in the blood.,The empirical equations were developed togive the relationship between parametersand hematocrit. Two other thixotropicparameters, viz. the kinetic rate constant ofrouleaux breakdown into individual red,cells and the order of the breakdownreaction, were found to be independent ofthe hematocrit. These results were consistantwith the reaction kinetic theory.