HEXAMETHYLENEBISACETAMIDE SELECTIVELY INHIBITS THE PROLIFERATION OF HUMAN AND RAT VASCULAR SMOOTH-MUSCLE CELLS

Hexamethylenebisacetamide (HMBA) selectively and reversibly inhibited proliferation of human and rat vascular smooth-muscle cells (VSMCs) compared with endothelial cells, fibroblasts or lymphocytes. Half-maximal inhibition of VSMC proliferation occurred at 2-5 mm-HMBA. and at 30- > 50 mm for other cell types. HMBA also prevented dedifferentiation, defined by the loss of smooth-muscle-specific myosin heavy chain, of primary rat VSMCs and caused partial re-differentiation of subcultured cells. Other inhibitors of ADP-ribosyltransferase were also selective inhibitors of VSMC proliferation.