The Effect of Irbesartan on Cardiomyocytes Hypertrophy and c-fos mRNA Expression Induced by Ang Ⅱ

ObjectiveTo study the effect of irbesartan （Irb） on hypertrophy of cardiomyocytes and c-fos mRNA expression induced by Ang Ⅱ.MethodsThe cardiomyocytes of Wistar rats were cultured with pancreatin and preplating technique and then divided into control and treatment groups.After irbesartan treatment for 30 min, Ang Ⅱ was added.Cell size was determined by phase contrast microscope and  3H-Leucine incorporation were determined;c-fos mRNA expression was assessed using reverse transcription polymerase chain reaction（RT-PCR）. ResultsCell size of cardiomyocyte of the group of Ang Ⅱ（29.2±3.1 vs 18.9±1.3 μm） was increased more prominently than the group of control （P＜0.05）.Compared with Ang Ⅱ group, irbesartan attenuated the increase of cardiomyocyte size（20.3±2.1 vs 29.2±3.1 μm, P＜0.05）.Cardiomyocyte protein synthesis rate in of Ang Ⅱ group（1 951±141 vs 1 123±121 cpm）（P＜0.01） was increased more significantly than the control group.Although Irbesartan didn’t affect the cardiomyocyte protein synthesis, it inhibited the increase of cardiomyocyte protein synthesis induced by Ang Ⅱ.Ang Ⅱ increased c-fos mRNA expression of cardiomyocyte evidently than that in control （0.921±0.104 vs 0.291±0.043）（P＜0.01）, which was inhibited by irbesartan（0.336±0.052 vs 0.921±0.104） （P＜0.01）. ConclusionIrbesartan prevent the hypertrophy of cardiomyocytes induced by Ang Ⅱ, which may be partially be to its inhibitory effect on the expression of c-fos mRNA.