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Quantitation of the Reticuloendothelial System Clearance of Soluble Fibrin
Author(s) -
Sherman L. A.,
Lee J.,
Jacobson A.
Publication year - 1977
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1977.tb06839.x
Subject(s) - plasmin , mononuclear phagocyte system , fibrin , chemistry , clearance , phagocytosis , fibrinogen , spleen , platelet , biochemistry , immunology , medicine , enzyme , urology
SUMMARY. Phagocytosis of particulate fibrin has been previously established as a function of the reticuloendothelial system (RES). More recently, reticuloendothelial cells have been shown to bind soluble fibrin/fibrinogen (f/F) complexes in vitro. To quantitate RES clearance us microthrombus formation, varying doses (0.1‐6 mg/kg) of 125 I‐soluble f/F was injected into rabbits. One hour later the animals were killed, at which time 48 $pM 8% of the 125 I f/F had been cleared from the blood. Homogenized organ samples were separated into insoluble pellet, soluble protein bound, and free 125 I. Treatment of other samples with plasmin prior to homogenization differentiated the insoluble 125 I into RES cleared (intracellular‐plasmin resistant) vs microthrombi (plasmin sensitive pellet 125 I). 125 I‐f/F was chiefly found in liver and spleen. Injection of low f/F concentrations resulted in no plasmin sensitive pellet 125 I. 3 mg/kg f/F caused small, variable amounts of plasmin sensitive pellet 125 I, chiefly in the kidney. With 6 mg/kg, 21‐50% of the insoluble 125 I in all organs was plasmin sensitive, and occasional 1–2 mm thrombi were found. The data indicate complete and rapid RES clearance of small amounts of soluble f/F from the blood, without microthrombi being formed. The RES was acutely saturated at 1.5–3.0 mg f/F/kg, which is equivalent to immediate conversion to fibrin of 1–2% of the intravascular fibrinogen pool.