[Intercellular communication studied by using the gap junctions in a primary cell culture of human aortic intima]

The rate of gap junction communication has been investigated in the primary culture of highly differentiated mesenchymal cells (subendothelial smooth muscle cells isolated from grossly normal and atherosclerotic areas of human aorta), and in poorly differentiated cells of mesenchymal origin (adult human skin fibroblasts as well as skin fibroblasts and aortic smooth muscle cells derived from human fetus). In cell cultures isolated from grossly normal and atherosclerotic aorta the number of cells coupled via gap junction increased with cell density and reached the plateau at a cell density of 50-70 cells/mm2. In cultures of normal aortic cells the number of coupled cells was significantly higher than in cultures of atherosclerotic cells. Gap junctional communication between cells loaded with lipid inclusions was lower that that between cells free of excess of intracellular lipids. In cultures of human skin fibroblasts the rate of intercellular communication was comparable to that in cultures of atherosclerotic cells. There was practically no cell-to-cell communication in cultures of fetal cells. It is hypothesized that the reduced gap junctional communication in atherosclerotic human aorta is associated with alterations in the degree of smooth muscle cell differentiation.