Abstract:

Objective To observe the effects of angiotensin Ⅱ receptor antagonist irbesartan on left ventricular hypertrophy and the expression of urea transporter B (UT-B) in myocardium of 5/6 nephrectomized rats with constricted abdominal aorta. Methods SD rats were randomly divided into the sham group, 5/6 nephrectomy group, abdominal aorta constriction group, 5/6 nephrectomy and abdominal aorta constriction group, and irbesartan group. Each group consisted of eight rats. Serum Cr, BUN, AngⅡ, and BNP were detected after rats were sacrificed. Rat hearts were harvested and the left ventricular weight/heart weight (LVW/HW), heart weight/body weight (HW/BW), and left ventricular weight/body weight (LVW/BW) were measured. The expression of UT-B in myocardium was determined by RT-PCR and Western blotting. Results Compared with the sham group, rats of 5/6 nephrectomy group, abdominal aorta constriction group, and 5/6 nephrectomy and abdominal aorta constriction group had the left ventricular hypertrophy and elevated LVW/HW, HW/BW, LVW/BW, serum AngⅡ, BNP, and mRNA and protein expressions of UT-B in myocardium. Levels of SCr and BUN of the 5/6 nephrectomy group and 5/6 nephrectomy and abdominal aorta constriction group increased. Compared with above three groups, rats of the irbesartan group had alleviated left ventricular hypertrophy and lower LVW/HW, HW/BW, LVW/BW, serum AngⅡ, BNP, and mRNA and protein expressions of UT-B in myocardium. Compared with the 5/6 nephrectomy group and 5/6 nephrectomy and abdominal aorta constriction group, levels of SCr and BUN of the irbesartan group were lower. Conclusion 5/6 nephrectomy and abdominal aorta constriction can cause significant decrease of heart function of rats, left ventricular hypertrophy, and elevated expression of UT-B. Irbesartan can improve heart and kidney functions and inhibit the expression of UT-B, which may play an important role in heart failure of rats with renal inadequacy.

Key words: irbesartan, urea transporter, 5/6 nephrectomy, constriction of the abdominal aorta, rat