Effects of diltiazem on myocardial remodeling of left ventricle in renal hypertensive rats

    CHEN Hui, ZHANG Ling, ZHU Dan, ZHOU Yiª²Wen, ZOU Lin, TU Zhiª²Guang

    Faculty of Laboratory Medicine, Chongqing University of Medical Sciences, Chongqing 400016, China

    ¡¾Abstract¡¿ AIM: To study the effects of diltiazem on the myocardial remodeling of left ventricle in renal hypertensive rats (RHR). METHODS: RHR model was established and received diltiazem (100 mg/kg, ig) q12 h continuously for 30 d. The index of the heart mass was compared between groups. A piece of tissue from the middle of the left ventricle was harvested, and the paraffin section and ultrathin section were prepared routinely and the microstructural and ultrastructural changes were observed respectively. Picrosirus red staining was performed and the changes of the collagen contents and of type ¢ñ to type ¢ó ratio were determined. RESULTS: Diltiazem decreased the ratios of heart mass/body mass and left ventricle mass/body mass slightly (by 8.8% and 9.7% respectively, P>0.05), kept the myocardium out of necrosis and inflammatory infiltration, and alleviated the myocardial hypertrophy. The ultrastructure was almost normal and only very few fields with slightly proliferated mitochondria were observed. Diltiazem reduced the collagen volume fraction and the integrity optical density significantly (by 47.3 % and 69.8 % respectively, P<0.01), and kept the ratio of collagen type ¢ñ to collagen type ¢ó from increasing. CONCLUSION: Diltiazem plays protective roles during the left ventricle remodeling of hypertension, especially in attenuating the hyperplasia of collagen. It reduces the blood pressure and improves the myocardial structure simultaneously. ......