Effect of rosiglitazone on the expression of angiotensin II type 1 receptor mRNA in mice vascular smooth muscle cells

Objective To investigate the expression of angiotensin Ⅱ type 1 receptor(AT_1R) mRNA in angiotensin Ⅱ-induced mice vascular smooth muscle cells(VSMC).Methods VSMC of mice in logarithmic growth phase(passage 6-10)were incubated with angiotensin Ⅱ(Ang Ⅱ 1μmol·L~(-1)) for 2h,and then were divided into A,B and C groups.20,30 or 50μmol·L~(-1) rosiglitazone were coincubated respectively with A,B and C groups for 12h.In addition,VSMC were incubated with Ang Ⅱ(1μmol·L~(-1)) for 6h,and then added 30mol L~(-1) rosiglitazone and coincubated for 0,6,12 or 24h.Total RNA was extracted.AT_1R mRNA in VSMC was determined by reverse transcription-polymerase chain reaction(RT-PCR).Results Compared with the control group(23.82±4.68),the expression of AT_1R mRNA of VSMC incubated with Ang Ⅱ was significantly increased(P0.01).The expression of AT_1R mRNA of VSMC was lower in the A or B or C group compared with Ang Ⅱ group(45.22±7.17、39.82±6.34、34.70±6.69 vs 61.04±12.20,respectively,P0.01).In addition, the expression of AT_1R mRNA was gradually decreased in VSMC when incubated with 30μmol·L~(-1) rosiglitazone for 0,6,12,24h.The expression of AT_1R mRNA in 6,12 or 24h was lower than that of 0h(46.99±4.81、39.82±6.34、35.71±6.13 vs 57.37±8.04,respectively,P0.01).(Conclusions )Rosiglitazone can attenuate the expression of AT_1R mRNA in angiotensin Ⅱ-induced VSMC as dose and time dependent manner.This may be one of the crucial mechanisms of rosiglitazone therapeutical effects in anti-atherosclerosis and anti-inflammatory.