HIGH D-GLUCOSE STIMULATES THE CELL-CYCLE FROM THE G1 TO THE S-PHASES AND M-PHASES, BUT HAS NO COMPETENT EFFECT ON THE G0 PHASE, IN VASCULAR SMOOTH-MUSCLE CELLS

The effects of high (28mM) D-glucose (HG) on the cell cycle progression were investigated in rat aorta vascular smooth muscle cells (VSMCs) in primary culture, using an immunocytochemical analysis of cell-cycle-specific nuclear antigens. HG had no effect on the cell cycle of the serum-deprived deprived G(0) cells, whereas platelet-derived growth factor (PDGF) stimulated the entry of the G(0) cells to the G(1) phase without a further progression to the S and M phases. HG, but neither mannitol nor L-glucose, stimulated the progression of the PDGF-pretreated G(1) cells to the S and M phases, was blocked by calphostin-C, a protein kinase C (PKC) blocker. HG did not affect the cytosolic Ca2+ concentration ([Ca2+]i). These data suggest that HG has no competent effect on the G(0) cells and acts as a progression growth factor (to stimulate the cell cycle from the G(1) to the S/M) in VSMCs through the mechanism, which may be insensitive to [Ca2+]i and mediated by PKC. (C) 1995 Academic Press, Inc.