Effects of two glycosaminoglycans on seeding of cardiac cushion tissue cells into a collagen-lattice culture system.

A collagen-lattice culture model of developing heart valves was utilized to test two glycosaminoglycans, normally found in the cardiac jelly matrix of developing heart valve primordia, for their effects on the capability of mesenchymal derivatives of cardiac cushion endothelial cells to enter the substrate from the surface. Treatment with hyaluronate increased the rate of cell seeding to 2.04 times that of untreated control cultures and 1.82 times that of chondroitin sulfate-treated cultures. Scanning electron microscopic studies suggested that the increased rate was due to an enhanced disruption of intercellular junctions, influenced by hyaluronate, permitting disengagement of cells from the surface population and migration as mesenchymal cells into the collagen matrix. The results of this study correlate well with the presence of high hyaluronate concentrations in the cardiac jelly matrix beneath the cushion endothelium at periods of active seeding of cushion tissue cells.