Effects of Angiotensin II Type 1 Receptor Antagonist on Nitric Oxide Synthase Expression and Myocardial Remodeling in Goldblatt Hypertensive Rats

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Abstract
We evaluated the effects of long-term treatment with TCV-116, an angiotensin II type 1 receptor antagonist, on endothelial-cell nitric oxide synthase (eNOS) messenger RNA (mRNA) and protein expression in the left ventricle and its relation to myocardial remodeling in Goldblatt hypertensive rats. Two-kidney, one-clip Goldblatt hypertensive rats (RHR) were assigned either to a TCV-116 treatment group (RHR-TCV, n = 8, 3 mg/kg/day, subdepressor dose) or to a group without treatment (RHR-V, n = 7) after their kidneys had been clipped for 4 weeks. TCV-116 was administered to rats in the treatment group for 6 weeks, and age-matched sham-operated rats (ShC, n = 7) served as a control group. Blood pressure in RHR-V and RHR-TCV was similar and significantly higher than that in ShC. The eNOS mRNA and protein levels and NOS activity in the left ventricle was significantly decreased in RHR-V compared with ShC, and significantly increased in RHR-TCV compared with ShC and RHR-V. RHR-V demonstrated a significant increase in fibrosis factor (type I collagen) mRNA expression, perivascular fibrosis, and myocardial fibrosis. These parameters in the microvasculature were improved significantly by TCV-116. Subdepressor dose of TCV-116 improved pathological myocardial changes in RHR, which may be due in part to an increased eNOS mRNA and protein expression and NOS activity in the left ventricle.