The experimental study of left ventricular assist device on local expression of AngII receptors mRNA of left ventricle in acute left heart failure canine model

Objective To evaluate the effect of left ventricular assist device(LVAD) on acute left heart failure canine model by the alteration of local AngII receptor(AT1/AT2) mRNA expression in left ventricular myocytes. Methods 15 canines were randomly divided into 3 groups: Control, hert failure(HF) and HF+LVAD groups. Acute left heart failure model was induced by occluding the left anterior descending coronary artery (LAD) or LAD+left circumflex coronary artery (LCX). The LVAD group was treated for 3 hours by pneumatic LVAD, whose output was 70?ml·kg. -1.·min. -1.. 100mg myocardium was taken from the left ventricle of each dog at 1, 2, 3 hours respectively. The expression of the local left ventricle AngII receptor (AT1/AT2) mRNA was tested by reverse transcription-polymerase chain reaction (RT-PCR). Results When compare with the control group, the expression of the AT1 mRNA in ischemic left ventricle decreased significantly in HF group after heart failure; AT2 mRNA in ischemic left ventricle increased significantly in HF group after heart failure. At 1, 2, 3 hours after LVAD, the AT1 mRNA level of the HF+LVAD group was higher than that of the HF group's, the AT2 mRNA level of the LVAD group was lower than that of the HF group's. Conclusion After heart failure, the expression of AT1 mRNA decreased, but it can be reversed by the LVAD. The expression of AT2 mRNA increased, and it can be reversed by the LVAD. The improvement of the AT1 mRNA and AT2 mRNA values in HF+LVAD group shows the improvement of left ventricular function.