β_1受体反义基因治疗对两肾一夹高血压大鼠血压及血流动力学的影响

Effects of β_1 receptor mRNA antisense inhibition on blood pressure and hemodynamics in acute 2-Kidney, 1-Clip hypertensive rats

目的 :探讨阳离子脂质体混合物 (DOTAP/DOPE)介导的 β1受体反义基因治疗对两肾一夹 (Gold blatt)肾性高血压大鼠血压及血流动力学的影响 ,寻求脂质体与 β1反义寡核苷酸 (β1 AS ODN)混合的最佳转染比例。方法 :用雄性SD大鼠制造两肾一夹 (Goldblatt)肾性高血压模型。β1寡核苷酸 (β1 ODN)末端用FITC标记 ,DOTAP/DOPE与 β1 AS ODN的摩尔比率分别为 0 ,1.5 ,2 .0 ,2 .5 ,3.0 ,经鼠尾静脉注射。监测血压 ,8周后测定血流动力学指标。结果 :FITC标记的 β1 AS ODN主要分布在非钳夹肾动脉一侧的肾近曲小管上皮细胞的细胞浆中。当比率为 2 .0时 ,可使血压下降维持 2 7d ,血压最大下降 39mmHg ,其降压效果及维持时间最好。比率 2 .0组的左心室收缩压、左室舒张末压降低 (P <0 .0 5 ,P <0 .0 1) ,左室最大收缩和舒张速率明显升高 (P <0 .0 1,P<0 .0 1) ,明显地改善了心功能。结论 :以 β1受体为靶基因的反义基因治疗有效 ,阳离子脂质体去掉可以增加静脉注射AS ODN的疗效 ;阳离子脂质体与 β1 AS ODN以不同的比率混合后注射 ,其降压效果及维持时间以及对血流动力学的影响有差异 ,当比率为 2 .0时最好。而且 β1 AS ODN没有中枢神经系统及减慢心率的不良反应。

Objective: To compare the antihypertensive effect of β 1 receptor antisense oligodeoxynucleotides (β1-AS-ODN) by delivery with the different charge ratios cationic liposomes DOTAP/DOPE and study its impact on the hemodynamics. Method:Five charge ratios of liposome/ODN 0, 1.5, 2.0, 2.5, 3.0 and inverted ODN were tested to deliver 0.5 mg/kg β 1-ODN (labeled with fluorescein) intravenously in rats with 2 kidney 1 clip hypertension. The β 1-AS-ODN at 48 hours was taken up into non-clipped kidney and remaining up to 7 days. The blood pressure was measured twice per week. The hemodynamic studies of the rats were performed after eight weeks.Result:On the basis of the magnitude and duration of hypotension, 2.0 was determined to be the optimal charge ratio, which decreased blood pressure by up to 39 mmHg for 27 days. Campared with the Sham group, left ventricular systolic pressure (LVSP) and left ventricular end diastolic pressure( LVEDP) were increased (P< 0.01,P< 0.01; respectively) and ±dp/dt were significantly decreased (P< 0.01,P< 0.01; respectively) inβ 1-IN-ODN group; campared with the β 1-IN-ODN group, LVSP and LVEDP were decreased (P< 0.05, P< 0.01; respectively) and ±dp/dt were significantly increased (P< 0.01,P< 0.01; respectively) in ratio 2.0 group. Conclusion:β 1-AS-ODN is a novel method of antihypertensive therapy. Cationic liposomes DOTAP/DOPE can improve the antihypertensive effects of β 1-AS-ODN and 2.0 was determined to be the optimal charge ratio. It also can improve hemodynamics and left ventricular function in 2 kidney 1 clip hypertensive rats.