Use of endothelium cultured on microcarriers as a model for the microcirculation.

The geometry of the vascular system is such that the surface area to volume ratio changes dramatically as a unit volume of blood circulates. Thus, it faces a surface area that is some 1000 times larger in the capillaries than in larger vessels. To approach the in vivo situation an in vitro model for the microcirculation was developed that uses endothelium cultured on microcarrier beads. Details of the culture method are presented. The cultures form confluent monolayers around the beads and resist removal by vigorous vortex mixing. Viability of the cells on the microcarrier is 100 per cent. The microcarrier cultures are packed into small columns (0.3 to 1.0 ml.) forming a perfusion system and used for studies of the binding of thrombin and platelet factor 4, for the demonstration of anticoagulant properties of the cells, for studies of the interaction between endothelium and platelets, and for the demonstration of prostacyclin release.