Heparin is an Anionic Hydrated Anticoagulant

Abstract

The major objective of this symposium is to seek substances and procedures by which blood can be kept flowing. The major determinant of whether blood continues to circulate or grows sluggish and forms an intravascular gel is the colloidal stability of fibrinogen (7, 8). Although fibrinogen constitutes only about 3–6% of total plasma protein, it is the dominant one in viscosity and gel formation (3). Fibrinogen continues to circulate normally as long as it carries a moderate negative charge and minimal degree of hydration on both its negative and positive polar sites. Reduction in either charge or hydration causes progressive shifts toward hypercoagulability, with increased surfactant property of the fibrinogen as it is driven from the plasma onto formed elements, vascular walls (4), and any other surface in or exposed to plasma. Progressive destabilization of fibrinogen causes marked increase in blood viscosity; aggregation and segregation of platelets, then of leukocytes, and then of red cells (Knisely sludging) (13); and finally disseminated intravascular coagulation. Dintenfass and Forbes (10) have shown increased viscosity of blood and plasma in many conditions in which gross hypercoagulability is later evident.