Beneficial effects of houttuynin on ventricular remodeling induced by coronary artery ligation in rats

To examine the effects of houttuynin on ventricular remodeling induced by coronary artery ligation in rats and the underlying mechanisms. A rat model of ventricular remodeling was established by left coronary artery ligation (CAL). Rats were randomly divided into four groups: CAL control, CAL plus 40 mg/kg captopril, CAL plus 100 mg/kg houttuynin and sham-operated control. The rats were administered intragastrically with the corresponding drugs or distilled water for 7 weeks. At the end of the experiment, the left ventricular weight index (LVWI) and heart weight index (HWI) were determined. Myocardium tissue was stained with hematoxylin and eosin or picric acid/Sirius red for cardiomyocyte cross-section area or collagen content measurements respectively. The concentrations of angiotensin I (Ang I), angiotensin II (Ang II), aldosterone (ALD) and endothelin-1 (ET-1) in myocardium or serum were detected by radioimmunoassay. The hydroxyproline (Hyp) concentration was measured by alkali hydrolysis. Ultraviolet spectrophotometry was used to determine glutathione peroxidase (GSH-Px) and catalase (CAT) activities in serum. Houttuynin significantly diminished LVWI and HWI, decreased Ang I, Ang II, ALD, ET-1 and Hyp concentrations in myocardium or serum, increased NO concentration and GSH-Px, CAT activities after 7 weeks of treatment. Houttuynin could also reduce cardiomyocyte cross-section area and collagen deposition. Houttuynin attenuates ventricular remodeling in coronary artery ligation rats by restricting the excessive activation of rennin-angiotensin-aldosterone system (RAAS) and the peroxidation.