Effect of angiotensin Ⅱ on the remodeling of aorta in spontaneously hypertensive rats / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effects of a 10-weeks treatment with angiotensin Ⅱ (Ang Ⅱ) subtype I receptor antagonist losartan on vascular remodeling of thoracic aorta in male spontaneously hypertensive rats (SHR). METHODS: SHR were treated from 16 to 26 weeks of age with losartan at 15 mg/kg?d -1 or 0.75 mg/kg?d -1. RESULTS: Losartan (15 mg/kg?d -1) treatment significantly decreased systolic blood pressure compared with the control group, while losartan (0.75 mg/kg?d -1) had no the effect, losartan(15 mg) prevents the development of aortic hypertrophy by preventing hypertrophy of vascular smooth muscle cells (VSMC). In the losartan 0.75 group, these parameters were not changed. But in the losartan 15 and losartan 0.75 groups, the collagen content of the aortic media decreased significantly. CONCLUSION: It is inferred that the effect of Ang Ⅱ on stimulating VSMC growth of the aorta in SHR is dependent on arterial pressure, while the effect on collagen fibers is through pressure independent mechanism.