Abstract:

Abstract:Objective
To investigate the expressions of both urotensin Ⅱ(UⅡ) and its receptor GPR14 in rat vascular smooth muscle cells (VSMC) under the intervention of urantide (UⅡ receptor antagonist),and clarify its possible mechanism.Methods The VSMC from rat thoracic aorta were cultivated in vitro with tissue explant method,and divided into normal control group (C group),UⅡ group (M group),positive control group (Flu group) and five intervention groups (10^-10,10^-9,10^-8,10^-7 and 10-6 mol·L^-1 urantide).The proliferation index(PI) and S-phase cell fraction(SPF) of  in vitro cultured VSMC were detected with MTT method and flow cytometry.Results Compared with C group,the VSMC proliferation was increased at each time point(P<0.01),and   PI and SPF were also increased significantly  (P<0.01);compared with M group, the VSMC proliferation in 10^-10－10^-6 mol·L^-1 urantide groups were significantly decreased(P<0.05 or P<0.01)，and PI and SPF were significantly reduced  (P<0.05 or P<0.01),among which 10-6 mol·L^-1 urautide group had the most significant effect. Conclusion Urantide can  block the mitogenic effect of  UⅡ on atherosclerosis(AS)  of the major disease-promoting cells VSMC,providing a new perspective and experimental basis for clinical application of urantide to treat AS.

Key words: urotensin Ⅱ;urantide;vascular smooth muscle cells;atherosclerosis