Appearance of platelet-clumping activity in heparinized plasma after acidification--it's mainly due to aggregation of fibrinogen.
Platelet-clumping activity was found after acidifying heparinized rabbit plasma to pH 5.5 in the presence of calcium ions. We tried to isolate the activity from plasma by gel filtration under low salt and high salt condition, and we found that the activity was related to the formation of plasma protein aggregates. Immunological examination and the results of fibrin monomer affinity chromatography indicated that fibrinogen was the main component of the plasma aggregates. This phenomenon was not related to the activation of blood coagulation. The binding of fibrinogen in the presence of heparin or calcium ions at low ionic strength may induce the appearance of platelet-clumping activity.
D000818:Animals; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004587:Electrophoresis, Agar Gel; D004589:Electrophoresis, Disc; D005337:Fibrin / Q000302:isolation & purification / Q000502:physiology; D005340:Fibrinogen / Q000502:physiology*; D006493:Heparin / Q000494:pharmacology*; D005779:Immunodiffusion; D046911:Macromolecular Substances; D010973:Platelet Adhesiveness / Q000187:drug effects; D011817:Rabbits
D046911:Macromolecular Substances; D005337:Fibrin; D005340:Fibrinogen; D006493:Heparin