True about Dextrain -
The reversible aggregation of human red blood cells (RBC) continues to be of interest in the field of hemorheology because RBC aggregation is a major determinant of the in vitro rheological propeies of blood. Enhanced aggregation increases low shear blood viscosity and the degree of non-Newtonian behavior (1,2). In addition, the in vivo flow dynamics and flow resistance of blood are influenced by RBC aggregation (3), and marked increases of RBC aggregation have been observed in several diseases associated with vascular disorders (e.g., diabetes mellitus, hypeension). Measures of RBC aggregation, such as the erythrocyte sedimentation rate (ESR), are commonly used as diagnostic tests and as one index to the efficacy of therapy. For example, ESR is measured during drug therapy for rheumatoid ahritis, and has been shown to be normalized by improved glycemic control in diabetes (4). There is now general agreement regarding the correlations between elevated levels of fibrinogen or other large plasma proteins and enhanced RBC aggregation, and the effects of molecular mass and concentration for neutral polymers have been repoed (5). However, the specific mechanisms involved in RBC aggregation have not been fully elucidated, and thus it is not yet possible to fully understand the relations between pathology and altered RBC aggregation. RBC form multicell linear or branched aggregates in vitro when they are suspended in either plasma or solutions containing large polymers (e.g., dextran >=40 kDa); RBC aggregates also form in vivo in regions of low flow or stasis and, hence, in regions of low shear. These linear forms are often termed rouleaux because they resemble a stack of coins. It is impoant to note that RBC aggregation is a reversible process, with aggregates dispersed by mechanical or fluid flow forces and then reforming when the forces are removed. Conversely, RBC agglutination and blood coagulation are irreversible processes due to either protein polymerization or strong antigen-antibody attractive forces. RBC aggregation is primarily determined by the type and concentration of polymers in solution or the plasma level of large proteins and by RBC aggregability (i.e., the intrinsic cell characteristics affecting RBC aggregation) In blood, the protein fibrinogen is a primary determinant of blood viscosity due to its strong tendency to increase both plasma viscosity and RBC aggregation In the past, most repos have primarily examined the ability of plasma proteins to promote aggregation; for example, higher fibrinogen levels have been linked to elevated blood viscosities in hypeensive patients Ref Harrison20th edition pg 1079
Cause Rouleaux formation
Impair factor VIIIO function
Sugar level
) Improve microcirculation
Infection