P2X (purinergic) receptor redistribution in rabbit aorta following injury to endothelial cells and cholesterol feeding

The redistribution of purinergic P2X receptor subunits (P2X(1) to P2X(7)) w ithin the rabbit aorta wall three weeks after endothelial balloon injury/ch olesterol feeding was examined. P2X(1) receptor cluster density was elevate d in the media following balloon injury/cholesterol feeding by about 30% an d these clusters appeared on smooth muscle cells throughout the greatly exp anded neointima but they did not change significantly on the endothelial ce lls following balloon injury. P2X(4) clusters were found in high density th roughout the media and in very high density in the enlarged neointima follo wing balloon injury, particularly on the endothelial cells where the densit y increased about 10-fold after balloon injury. P2X(5) clusters were found in high density in the media of normal aorta but with little change followi ng balloon injury. P2X(3), P2X(6) and P2X(7) cluster density was low in nor mal aorta and remained unchanged following balloon injury. All receptor sub units were found on endothelial cells. It is suggested that the release of ATP from damaged endothelial cells and from smooth muscle cells sufficient to activate P2X(4) receptors may contribute to neointimal proliferation.