Effects of benazepril and irbesartan on myocardial collagen in chronic heart failure rats and mechanisms / 中国药理学通报

ABSTRACT

Aim To observe the effects of benazepril and irbesartan on myocardial collagen in chronic heart failure ( CHF ) rats and the possible mechanisms. Methods CHF model in rats was made by partially banding abdominal aorta to induce pressure overload cardiac hypertrophy. The rats were given benazepril or/and irbesartan for 8 weeks. Systolic blood pressure ( SBP) was monitored by rat tail artery. The ultrastruc-ture of myocardium was detected by transmission elec-tron microscope. The content of myocardial hydroxyproline and amount of cross-linked collagen were measured by hydrolysis method. The expression of type Ⅰ and Ⅲ collagen protein in myocardium was investigated by immunohistochemistry. The expression of p-38 MAPK and p-p38 MAPK proteins was detected by Western blot. Results Compared with the model of CHF, there was no significant difference in SBP af-ter treatment. The content of hydroxyproline in myocar-dium, degree of cross-linked collagen, as well as ex-pression of type I collagen, type Ⅲ collagen and p-p38 MAPK proteins were significantly decreased after treatment with benazepril or irbesartan ( P <0. 05 ) , and the combined treatment of them had better effects. Conclusion There is a synergistic effect of attenua-ting the quantity and quality of myocardial collagen in CHF rats by combined use of benazepril and irbesar-tan, which may be related to the down regulation of p-p38MAPK protein expression.