Abstract
The effects of fibrinogen, globulin, albumin, and packed blood cell volume (hematocrit) on the kinetics of erythrocyte aggregation (RBC-A) after stasis were quantitatively evaluated by recording the changes of light transmission through the blood in transparent tubing with an apparatus consisting of a light-emitting diode and a silicon photodiode. The measurements were done on samples of heparinized whole blood, suspensions of erythrocytes containing various concentrations of fibrinogen (0.5 to 25 g/L) or gamma globulin (25 to 150 g/L), and blood of various hematocrit values prepared from three samples of whole blood having different concentrations of fibrinogen. The half-time of the increase of light transmission after the flow-stop was used as an index of the kinetics of RBC-A (T1/2). This simple and rapid method for estimating erythrocyte aggregation had excellent reproducibility (N = 51, r = 0.99). The values of T1/2 showed significant negative correlations with the concentrations of fibrinogen and globulin but a positive correlation with that of albumin. The T1/2 value decreased markedly and then remained almost constant with increase in the value of hematocrit, but the influence of hematocrit on T1/2 was markedly dependent on the concentration of fibrinogen.