Effect of breviscapine on proliferation and expression of thrombin receptor mRNA of cultured Pat vascular smooth muscle cells

Abstract

Objective To investigate the effect of breviscapine on the proliferation and the expression of thrombin receptor mRNA of vascular smooth muscle cells (VSMCs) . Methods Rat thoracic aortic VSMCs cultivated in vitro were randomly assigned to control,breviscapine 0.5 μg/mL, 5 μg/mL and 50 μg/mL groups, The proliferation was induced by thrombin, The proliferative effect of VSMCs was measured by the3H-thymidine (3H-TdR) incorporation method; the expression intensity of thrombin receptor mRNA relative to β-actin mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). Results The incorporation rate (cpm/1. 5 × 105 cells) of3H-TdR were 1 216. 00±241.57,673.25±12.63,602.50±80.59, and 522.00±103.99 respectively in the control, and breviscapine 0. 5 μg/mL, 5 μg/mL and 50 μg/mL groups. As compared with the control group, the prolifera-tion of rat thoracic aortic VSMCs was inhibited significantly in all breviscapine groups (all P<0.05). RT-PCR showed that the expressions of thrombin receptor mRNA relative to β-actin mRNA were 0. 614, 0. 389, 0. 310, and 0. 280 respectively in the control, and breviscapine 0. 5μg/mL, 5μg/mL and 50 μg/mL groups, The expression ratios of TR/β-actin mRNA in thoracic aortic VSMCs in all the breviscapine groups were lower than those in the control group, which suggesting that the expression of thrombin receptor mRNA was inhibited. Conclusions Breviscapine inhibits the proliferation of rat VSMCs. Its mechanism may he associated with the inhibition of the thrombin receptor gene expression of VSMCs.