三黄降糖方对糖尿病大鼠心肌局部肾素-血管紧张素系统的作用

目的 研究三黄降糖方对糖尿病大鼠心肌病变的作用及对心肌肾素一血管紧张素系统(RAS)的影响。方法 腹腔注射链脲菌素(STZ)造成大鼠糖尿病模型，于造模后2周起分别灌胃三黄降糖方(50g／kg)、达美康(20mg／kg)、卡托普利(15mg／kg)和尼群地平(30mg／kg)，连续8周，检测空腹血糖、血清胰岛素(Ins)、心脏／体重比值及心肌血管紧张素Ⅱ(AngⅡ)、血管紧张素转换酶(AC：E)和醛固酮(ALD)，以逆转录一聚合酶链式反应(RT-PCR)检测心肌血管紧张素Ⅰ型受体(ATIR)mRNA表达。结果 与正常对照组比较，模型对照组空腹血糖升高(P<0．01)，血清Ins水平降低(P<0．01)，心脏／体重比值升高(P<0．01)，心肌AngⅡ含量增加(P<0．01)，ACE活性升高(P<0．01)，ALD含量增加(P<0．05)，心肌ATIR mRNA表达增加(P<0．05)。三黄降糖方、达美康、卡托普利和尼群地平均可使模型大鼠血糖轻微降低，但各药均不升高血清Ins水平。三黄降糖方、达美康、卡托普利和尼群地平均可使心脏／体重比值下降，心肌AngⅡ含量、ACE活性和ATIR mRNA表达量均下降，三黄降糖方和卡托普利还可使心肌ALD含量降低。结论 在糖尿病病程10周，可引起心肌肥大，心脏局部RAS激活与糖尿病心肌病变的发生有关；三黄降糖方、达美康、卡托普利和尼群地平均可对抗糖尿病心肌病变，其作用与抑制心脏局部RAS激活有关。

Effect of Sanhuang Jiangtang Recipe on Renin-Angiotensin System in Local Myocardium in Diabetic Rats

OBJECTIVE: To study the effect of Sanhuang Jiangtang recipe (SJR) on renin-angiotensin system in local myocardium in diabetic rats. METHODS: Rats were made into diabetes model by intraperitoneally administering of streptozocin, and medicated through gastrogavage with SJR (50 g/kg), gliclazide (20 mg/kg), captopril (15 mg/kg) and nitrendipine (30 mg/kg) respectively, for successive 8 weeks, started from 2 weeks after modeling. Levels of fasting blood sugar (FBS), serum insulin (Ins), heart/body weight ratio (H/BW), myocardial angiotensin II (Ang II), angiotensin converting enzyme (ACE) and aldosterone (ALD) were determined. And the mRNA expression of type I angiotensin receptor (AT1R) in myocardium were detected by RT-PCR assay. RESULTS: As compared with those in the normal rats, levels of FBS, H/BW, Ang II, ACE, ALD and AT1R mRNA expression were higher (all P < 0.05) and level of serum Ins was lower (P < 0.01) in the model rats. SJR, gliclazide, captopril and nitrendipine could slightly reduce the blood sugar level in model rats, but with no increase of serum Ins. All the four drugs could reduce H/BW, Ang II, ACE and AT1R mRNA expression. SJR and captopril could also decrease the ALD content in myocardium. CONCLUSION: Cardiac hypertrophy has been induced in 10 weeks after diabetic modeling. Activation of local myocardial RAS is related to the genesis of diabetic cardiomyopathy. SJR, gliclazide, captopril and nitrendipine could antagonize the genesis of diabetic cardiomyopathy, the mechanism is related to the inhibition of RAS activation in local myocardium.