Summary
An investigation has been made of the effect of fibrinogen concentration and fibrinogen
degradation products on the flexibility of erythrocytes. The measurements were made
using the blood of 2 donors, one representative of the normal population, the other
representative of the 1. 5% of the normal population whose flexibility is more than
three standard deviations from the total population mean. A linear relationship between
erythrocyte flexibility and fibrinogen concentration was found in both cases. However,
while the normal control had only a slow packing rate at zero fibrinogen concentration,
the fast-packing cells retained a high degree of flexibility. Digestion of fibrinogen
for sufficient time to form the larger degradation fragments X and Y indicated that
they have similar effects to the native fibrinogen. The smaller fragments D and E,
do not affect the flexibility nor do they inhibit or modify the effect of fibrinogen.
