Summary
The fibrinogen molecule has a number of biological activities and some of these are
shared by the larger degradation products. This study was carried out to investigate
the erythrocyte sedimentation-accelerating property of fibrinogen and how this property
might be modified by proteolytic digestion with plasmin.
The sedimentation rate of washed human red cells suspended in saline, was found to
be directly proportional to the concentration of added purified human fibrinogen,
down to 250 mg%, below which there was no difference from saline controls. Plasmic
digestion of fibrinogen yielding fragment X, did not reduce the accelerating affect
on erythrocyte sedimentation, indicating that the intact carboxyl terminal end of
the Aα chain is unnecessary for this phenomenon. Further digestion to fragment Y reduced
the effect slightly but digestion to fragments D and E abolished the accelerating
effect completely.
