Objective: To investigate the effects of evodiamine(Evo), a component of Evodiaminedia rutaecarpa(Juss.) Benth, on cardiomyocyte hypertrophy induced by angiotensin Ⅱ(Ang Ⅱ) and further explore the potential mechanisms. Methods: Cardiomyocytes from neonatal Sprague Dawley rats were isolated and characterized, and then the cadiomyocyte cultures were randomly divided into control, model(Ang Ⅱ 0.1 μmol/L), and Evo(0.03, 0.3, 3 μmol/L) groups. The cardiomyocyte surface area, protein level, intracellular free calcium([Ca^(2+)]i) concentration, activity of nitric oxide synthase(NOS) and content of nitric oxide(NO) were measured, respectively. The m RNA expressions of atrial natriuretic factor(ANF), calcineurin(CaN), extracellular signal-regulated kinase-2(ERK-2), and endothelial nitric oxide synthase(e NOS) of cardiomyocytes were analyzed by real-time reverse transcriptionpolymerase chain reaction. The protein expressions of calcineurin catalytic subunit(CnA) and mitogen-activated protein kinase phosphatase-1(MKP-1) were detected by Western blot analysis. Results: Compared with the control group, Ang Ⅱ induced cardiomyocytes hypertrophy, as evidenced by increased cardiomyocyte surface area, protein content, and ANF m RNA expression; increased intracellular free calcium([Ca^(2+)]i) concentration and expressions of CaN m RNA, CnA protein, and ERK-2 m RNA, but decreased MKP-1 protein expression(P<0.05 or P<0.01). Compared with Ang Ⅱ, Evo(0.3, 3 μmol/L) significantly attenuated Ang Ⅱ-induced cardiomyocyte hypertrophy, decreased the [Ca^(2+)]i concentration and expressions of CaN m RNA, CnA protein, and ERK-2 m RNA, but increased MKP-1 protein expression(P<0.05 or P<0.01). Most interestingly, Evo increased the NOS activity and NO production, and upregulated the e NOS m RNA expression(P<0.05). Conclusion: Evo significantly attenuated Ang Ⅱ-induced cardiomyocyte hypertrophy, and this effect was partly due to promotion of NO production, reduction of [Ca^(2+)]i concentration, and inhibition of CaN and ERK-2 sign
HE NaGONG Qi-haiZHANG FengZHANG Jing-yiLIN Shu-xianHOU Hua-huaWU QinSUN An-sheng
Objective:To evaluate the effects and possible mechanisms of rutaecarpine on angiotensinⅡ(AngⅡ)-induced proliferation in cultured rat vascular smooth muscle cells(VSMCs).Methods:VSMCs were isolated from Male Sprague-Dawley rat aorta,and cultured by enzymic dispersion method.Experiments were performed with cells from passages 3-8.The cultured VSMCs were randomly divided into control,model(AngⅡ0.1μmol/L),and rutaecarpine(0.3-3.0μmol/L)groups.VMSC proliferation was induced by AngⅢ,and was evaluated by the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cell counting.To examine the mechanisms involved in anti-proliferative effects of rutaecarpine,nitric oxide(NO)levels and NO synthetase(NOS)activity were determined.Expressions of VSMC proliferation-related genes including endothelial nitric oxide synthase(eNOS),and c-myc hypertension related gene-1(HRG-1)were determined by real-time reverse transcription-polymerase chain reaction(RT-PCR).Results:Rutaecarpine(0.3-3.0μmol/L)inhibited AngⅡ-induced VSMC proliferation and the best effects were achieved at 3.0μmol/L.The AngⅡ-induced decreases in cellular NO contents and NOS activities were antagonized by rutaecarpine(P<0.05).AngⅡadministration suppressed the expressions of eNOS and HRG-1,while increased c-myc expression(P<0.05).All these effects were attenuated by 3.0μmol/L rutaecarpine(P<0.05).Conclusion:Rutaecarpine is effective against AngⅡ-induced rat VSMC proliferation,and this effect is due,at least in part,to NO production and the modulation of VMSC proliferation-related gene expressions.
Objective: To investigate the effect and potential mechanisms of rutaecarpine(Rut) in a rat artery balloon-injury model. Methods: The intimal hyperplasia model was established by rubbing the endothelia with a balloon catheter in the common carotid artery(CCA) of rats. Fifty rats were randomly divided into five groups, ie. sham, model, Rut(25, 50 and 75 mg/kg) with 10 rats of each group. The rats were treated with or without Rut(25, 50, 75 mg/kg) by intragastric administration for 14 consecutive days following injury. The morphological changes of the intima were evaluated by hematoxylin-eosin staining. The expressions of proliferating cell nuclear antigen(PCNA) and smooth muscle(SM) α-actin in the ateries were assayed by immunohistochemical staining. The m RNA expressions of c-myc, extracellular signal-regulated kinase 2(ERK2), MAPK phosphatase-1(MKP-1) and endothelial nitric oxide synthase(e NOS) were determined by real-time reverse transcription-polymerase chain reaction. The protein expressions of MKP-1 and phosphorylated ERK2(p-ERK2) were examined by Western blotting. The plasma contents of nitric oxide(NO) and cyclic guanosine 3',5'-monophosphate(c GMP) were also determined. Results: Compared with the model group, Rut treatment significantly decreased intimal thickening and ameliorated endothelial injury(P<0.05 or P<0.01). The positive expression rate of PCNA was decreased, while the expression rate of SM α-actin obviously increased in the vascular wall after Rut(50 and 75 mg/kg) administration(P<0.05 or P<0.01). Furthermore, the m RNA expressions of c-myc, ERK2 and PCNA were downregulated while the expressions of e NOS and MKP-1 were upregulated(P<0.05 or P<0.01). The protein expressions of MKP-1 and the phosphorylation of ERK2 were upregulated and downregulated after Rut(50 and 75 mg/kg) administration(P<0.05 or P<0.01), respectively. In addition, Rut dramatically reversed balloon injury-induced decrease of NO and c GMP in the plasma(P<0.05 or P<0.01). Conclusion: Rut could inhibit the balloon injury-indu
