Effects of Qiangxinyiqi Decoction on Myocardial Hypertrophy and Mechanisms Involved in RAAS,CaN Singnal Transduction in Rats

Objective To observe the effects of Qiangxinyiqi Decoction(QXYQD) on myocardium remodeling and to explore the mechanisms in rats with pressure overload.Methods Pressure overload rat model was established by partly constricting the abdominal aortas.Forty-eight adult male SD rats were randomized into 4 groups: sham operation group(SOG),operation group(OG),low-dose QXYQD group(L-QXYQD G,24 g·kg-1·d-1),high-dose QXYQD group(H-QXYQD G,72 g·kg-1·d-1).L-QXYQD G and H-QXYQD Gs were orally administered QXYQD once a day from 4th to 8th weeks.The other 2 groups were given the same amount of normal saline in the same way.The contents of angiotensin(Ang Ⅱ),aldosterone(ALD) and activity of calcineurin(CaN),and left ventricular weight index(LVMI) of the four groups were recorded;cardiac myocyte diameters(MD) and collagen volume fraction(CVF) were determined by video densitometry the 8th week.Results(1) Compared with SOG group,the Ang Ⅱ,ALD and CaN in OG group increased significantly;compared with OG group,those of treatment groups were decreased significantly.(2) Compared with SOG group,the content of collagen accompanied by the myofibrilla in OG group,the LVMI,MD and CVF were higher with significant difference;compared with OG group,those of treatment groups were lower with significant difference.Conclusion Qiangxinyiqi Decoction has beneficial effects on myocardium remodeling,and can lighten and postpone the accumulation of myocardial collagen of rats with pressure overload;the mechanism involved in decreasing the contents of Ang Ⅱ,ALD and activity of CaN.