Study of imidapril and irbesartan inhibiting remodeling of left ventricle in spontaneously hypertension rats

Objective:To research effects of imidapril and irbesartan on inhibiting remodeling of left ventricle in spontaneously hypertensive rats and compare their effects. Methods: Thirty of 13 weeks old spontaneously hypertensive rats were randomly divide into three groups: SHR positive control group, imidapril treating group(3mg. kg-1 .d-1), irbesartan treating group(50 mg.kg-1d-1), ten homogenous Wistar-Kyoto rats were selected as normal control group. Monitoring blood pressure of rats periodically; after 15 weeks, putting all rats to death, taken out heart, measuring left ventricle weight(LVW) and thickness, then computing LVW/BW and left ventricle thickness/BW; Specimen of left ventricle was observed by light and transmission electron microscope; Ang II and ANF level of plasma and left ventricular myocardium were measured by radioimmunoassay. Results: Blood pressure and LVW/BW, left ventricle thickness/BW, ANF level of plasma and left ventricular myocardium of imidapril group and irbesartan group were lower than those of SHR group. Imidapril group and irbesartan group had no difference in these indexes; Ang II level of plasma, left ventricular myocardium in SHR group were same or lower that those in WKY group and the levels in irbesartan group was higher and in imidapril group were lower than that in SHR group; Left ventricle modulation in structure especially fibrosis was slighter in imidapril group and in irbesartan group. Furthermore, modulation of imidapril group was slighter than that of irbesartan group. Conclusions: Not only imidapril and irbesartan can controll blood pressure well but also they can inhibit remodeling of left ventricle in SHR; Imidapril is better than irbesartan in preventing left ventricle from modulation in structure especially fibrosis.