Effects of angiotensin II on the proliferation and apoptosis of vascular smooth muscle cells

Objective: To study the effects of angiotensinⅡ(AngⅡ) on the proliferation and apoptosis of vascular smooth muscle cells (VSMCs). Methods: The cell proliferation was detected by the methods of MTT, cell number counting and 3H-TdR incorporation, cell cycle and apoptosis ratio were determined by flow cytometry, and cell ultramicrostructure was observed under transmission electron microscope. Results: AngⅡ promoted VSMCs proliferation, and the effect had a positive relation to AngⅡconcentration. It had no effect on VSMCs apoptosis in low and moderate concentrations, but high concentration of AngⅡinduced the apoptosis of VSMCs. AngⅡmade VSMCs transform from G0/G1 to S/G2-M phase, and promoted the transition of VSMCs from contractile to synthetic phenotype. Conclusion: The effect of promoting proliferation on VSMCs of AngⅡ has a concentration- and time-depending style, AngⅡin high concentration induces the apoptosis of VSMCs.