| Part I. Effect of PMQ on hemodynamics in anaesthetic normal blood pressure ratsObjective: To observe the effect of PMQ on hemodynamics in anaesthetic normal blood pressure rats. Methods: Fifty rats were randomly assigned to the 5 groups with 10 rats in each group: group NS, solvent and PMQ groups (low, middle, high dose). After orperation hemodynamic data was monitored including artery blood pressure (SP, DP, MAP, PPD), left ventricular function (HR, LVSP, LVDP,±dp/dtmax, T-dp/dtmax). PMQ was administered by duodenum cannula. Results: Compared with solvent group, three doses PMQ improves +dp/dtmax and LVSP, and the effect are dose-dependented. In addition, high dose PMQ significantly increases HR, reduces t-dp/dtmax and diastolic pressure. Conclusion: Three doses PMQ all increase cardiac function and the effect is dose-dependented. High dose PMQ decreases diastolic blood pressure.Part II. Effect of PMQ on hemodynamics in hypertensive rats induced by Angiotensin IIObjective: To study the effect of PMQ on hemodynamics in hypertensive rats induced by Ang II. Methods: Thirty rats were randomly assigned to the 5 groups with 6 rats in each group: (1) control group: Saline gavage was performed daily for 21 days; (2) PMQ group: PMQ (50mg/kg) gavage was performed daily for 21 days; (3) Ang II group: Ang II(288μg/kg?d)was daily injected subcutaneously from the 15th day; (4) PMQ + Ang II group: PMQ gavage and Ang II injection were performed as the same as above; and (5) vehicle + Ang II group: Vehicle (0.5% PVP) gavage was performed daily for 21 days, Ang II injection was performed as the same as above. At 22st day, hemodynamic data was monitored. Results: PMQ reduced blood pressure and increased +dp/dtmax in the Ang II induced hypertensie rats. Conclusion: PMQ depress blood pressure and improve heart function in the Ang II induced hypertension rats.Part III. Pentamethylquercetin protects the heart against the reperfused injury in rat by intravenous infusionObjective: PMQ was intravenous infused to observe the protective effect of against reperfused myocardium injery. Methods: 30 SD male rats were randomly divided into 3 groups with 10 in each group: (1) model group; (2) solvent group; (3) PMQ group;. Acute myocardial infarction was induced in rats by the ligation of coronary artery anterior descending branch. All rats underwent 30 min ischemia and following 120 min reperfusion. Hemodynamic data was monitored both ischemia and reperfusion duration. At the end of 120 min reperfusion the hearts were removed for determination of myocardial infarct size and serum superoxide dismutase (SOD) activity and malonaldehyde (MDA) concentration were also measured. Results: In PMQ group, LVSP and + dp/dtmax recovered significantly better than solvent group (P<0.05). In PMQ group serum MDA content,LDH and myocardial infarct size were significantly lower than solvent group (P<0.0 5).The contractility of cardiac muscle and serum SOD were significantly higher than solvent group (P<0.0 5).Conclusion: Our findings suggest PMQ 5μg/kg intravenous injected can improve cardiac function damaged by ischemia/reperfusion, reduce infarct size. The antioxidation may be one of the mechanisms in actions of PMQ.Part IV. Pentamethylquercetin protects the heart against the reperfused injury in rat pretreated by intragastric administration of PentamethylquercetinObjective: PMQ was intragastric administed for 6 days to observe the protective effect of PMQ against myocardiac injury induced by ischemia/reperfusion in rat. Methods: 20 male SD rats were divided into 2 groups randomly with 10 in each group. (1) solvent group; (2)PMQ group. Acute myocardial infarction was induced in rats by coronary artery ligation. All rats'hearts underwent 30min ischemia and following 120min reperfusion. Hemodynamic data was monitored both ischemia and reperfusion duration. The concentrations of lactate dehydrogenase (LDH) and creatine phosphokinase (CK) in serum, myocardial superoxide dismutase (SOD) activity and malonaldehyde (MDA) content were measured. Myocardial ultrastruture was observed. Myocardial apoptosis, expression of antiapoptotic protein Bcl-2 and proapoptotic protein Bax were detected. Results: Compared with solvent group, PMQ can remarkablely improve–dp/dtmax and SP (P<0.05); decreased concentrations of LDH and CK in the serum (P<0.05); reduced the injury of myocardial ultrastruture and apoptosis of myocardium; increased the protein expression of Bcl-2 gene, reduced the protein expression of Bax gene; increased myocardial activity of SOD and reduced content of MDA(P<0.05),. Conclusion: Our findings suggest PMQ 50mg/kg intragastric administration for 6 days can improve cardiac function and ultrastruture changes damaged by ischemia/reperfusion and reduced apoptoses. The antioxidation may be one of the mechanisms in actions of PMQ. |
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