ABSTRACT
During a lecture given in 1786, John Hunter stated that In all inflammatory dispositions, blood has an increased disposition to separate into its component parts, the red globules become less uniformly diffused and their attraction to one another becomes stronger, so that the blood, when spread over any surface, it appears mottled, the red blood attracting itself and forming spots of red. Dextran has been used in clinical practice for 20 or more years to improve blood flow, the raison d'être being partly on its ability to reverse the aggregation of erythrocytes in whole blood. However, while low molecular weight dextran will inhibit rouleaux formation, high molecular weight material has the reverse effect, producing rouleaux which are morphologically similar to those generated by plasma. The study of dextran has given very considerable insight into the physicochemistry of rouleaux formation, but is limited by its electrical neutrality.
