The impact of platelet derived growth factor-BB on in vitro cultured rat vascular smooth muscle cell proliferation and ras protein expression

Objective To investigate the impact of platelet derived growth factor-BB (PDGF-BB)on in vitro cultured rat vascular smooth muscle cell (VSMC) proliferation and its ras protein expression.Methods VSMCs were obtained from SD rat weighing about 200 g and cultured in vitro. After subculture for three times, VSMCs were transferred into 24-hole culture plate and divided into four groups: control group, and three experimental groups intervened with concentrations of 1, 2 and 4 μg/L PDGF-BB. The proliferation, ras protein expression of VSMCs and the correlation between the two indexes were evaluated by cell counting, immunohistochemical and immunofluorescence methods respectively at 3 time points: 1st,3rd and 7th day. Results ( 1 ) Within 7 days, VSMCs were increased gradually in all 4 groups. The cell count in 2 μg/L and 4 μg/L PDGF-BB groups was increased more faster than in control group, and that in 4 μg/L LDGF-BB group was increased more faster than 1 μg/L LDFG-BB group (P ＜0.05). (2) Immunostaining and immunofluorescence showed that proliferation cell nuclear (PCNA) expression of VSMCs in higher concentration PDGF-BB group was significantly higher than in lower concentration PDGF-BB group ( P ＜ 0.05 ) after intervention for 3 days. A likewise trend could be detected in ras protein expression of VSMCs ( P ＜ 0.01 ). The expression of ras protein in VSMCs was significantly positive correlation with that of PCNA ( r = 0.735, P ＜ 0.05 ). Conclusion PDGF-BB stimulates the proliferation of in vitro cultured rat VSMCs and increases its ras protein expression. Key words: Vascular smooth muscle cell;  Platelet derived growth factor;  Proliferation;  Ras protein