OBJECTIVETo study the effect of Sanhuang Jiangtang recipe (SJR) on renin-angiotensin system in local myocardium in diabetic rats.

METHODSRats 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.

RESULTSAs 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.

CONCLUSIONCardiac 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.