Losartan attenuates vascular remodeling of the aorta in spontaneously hypertensive rats and the underlying mechanism / 中南大学学报(医学版)

ABSTRACT

Objective To determine the effect of losartan on vascular remodeling and the underlying mechanism in spontaneously hypertensive rats(SHR). Methods SHR of 12 weeks old were given losartan orally [0,15,30 mg/(kg·d),n=12]. The tail arterial pressure was measured every week.Eight weeks later, the pathological changes and p22phox expression in the thoracic aorta, the activity of catalase (CAT), the contents of H2O2 and AngⅡ in the plasma were evaluated. Results Blood pressure was increased in the SHR accompanied by the thickened wall and increased p22phox expression in the thoracic aorta. The plasma levels of H2O2 and AngⅡwere elevated while the CAT level was decreased in the SHR. Administration of losartan reversed the thickened wall and increased the CAT activity concomitantly with the decreased plasma levels of H2O2 and p22phox expression in the SHR. The plasma level of AngⅡincreased after the losartan treatment. Conclusion Oxidative stress induces the vascular remodeling of the aorta in the SHR. Losartan can reverse the vascular remodeling through down-regulating p22phox expression and inhibiting the oxidative stress.