Some factors affecting fibrinogen precipitation by ristocetin:
ultrastructure of precipitates
C Ts'ao, D Green and EC Rossi
Fibrinogen in aqueous solution is precipitated by the antibiotic
ristocetin. This reaction is inhibited by albumin and facilitated by low
temperature. Resolubilized fibrinogen clots in the presence of thrombin.
Ristocetin-precipitated fibrinogen takes the form of fibrils or clumps,
composed of irregularly spaced, structure-less particles. The addition of
ristocetin to washed platelets suspended in fibrinogen- containing media
produces fibrinogen clumps in both the media and in the surface
cannalicular system of the platelets. The changes in light transmission
(aggregation curves) are due to both platelet aggregation and fibrinogen
clumping. The role of the latter is confirmed by the observation that the
addition of ristocetin to inert latex particles suspended in fibrinogen
solution produces typical aggregation curves. This phenomenon is prevented
by the addition of albumin to the media. We conclude that (1) if fibrinogen
is present in any artificial system, albumin should be included in the
media to prevent fibrinogen precipitation; and (2) statements about
aggregation of any particulated materials by ristocetin should not be based
solely on light- transmission changes, but should also include a
description of the morphologic appearance.
Volume 45,
Issue 5,
pp. 621-629,
05/01/1975
Copyright © 1975 by The American Society of Hematology
