Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands.
Am J Physiol Heart Circ Physiol. 2010 Dec;299(6):H2037-45. doi: 10.1152/ajpheart.00400.2010. Epub 2010 Sep 17.
We recently developed a rat model of cardiorenal failure that is characterized by severe left ventricular systolic dysfunction (LVSD) and low nitric oxide (NO) production that persisted after temporary low-dose NO synthase inhibition. We hypothesized that LVSD was due to continued low NO availability and might be reversed by supplementing NO. Rats underwent a subtotal nephrectomy and were treated with low-dose NO synthase inhibition with N(ω)-nitro-l-arginine up to week 8. After 3 wk of washout, rats were treated orally with either the long-acting, tolerance-free NO donor molsidomine (Mols) or vehicle (Veh). Cardiac and renal function were measured on weeks 11, 13, and 15. On week 16, LV hemodynamics and pressure-volume relationships were measured invasively, and rats were killed to quantify histological damage. On week 15, blood pressure was mildly reduced and creatinine clearance was increased by Mols (both P < 0.05). Mols treatment improved ejection fraction (53 ± 3% vs. 37 ± 2% in Veh-treated rats, P < 0.001) and stroke volume (324 ± 33 vs. 255 ± 15 μl in Veh-treated rats, P < 0.05). Rats with Mols treatment had lower end-diastolic pressures (8.5 ± 1.1 mmHg) than Veh-treated rats (16.3 ± 3.5 mmHg, P < 0.05) and reduced time constants of relaxation (21.9 ± 1.8 vs. 30.9 ± 3.3 ms, respectively, P < 0.05). The LV end-systolic pressure-volume relationship was shifted to the left in Mols compared with Veh treatment. In summary, in a model of cardiorenal failure with low NO availability, supplementing NO significantly improves cardiac systolic and diastolic function without a major effect on afterload.
我们最近开发了一种心肾衰竭的大鼠模型,其特征是严重的左心室收缩功能障碍(LVSD)和低一氧化氮(NO)产生,这种情况在短暂的低剂量 NO 合酶抑制后仍然存在。我们假设 LVSD 是由于持续的低 NO 供应不足引起的,并且可能通过补充 NO 来逆转。大鼠接受了部分肾切除术,并在第 8 周之前接受低剂量的 NO 合酶抑制剂 N(ω)-硝基-L-精氨酸治疗。在洗脱 3 周后,大鼠口服长效、无耐受的 NO 供体 molsidomine(Mols)或载体(Veh)。在第 11、13 和 15 周测量心肾功能。在第 16 周,通过侵入性测量 LV 血流动力学和压力-容积关系,并杀死大鼠以定量组织学损伤。在第 15 周,Mols 治疗轻度降低血压和增加肌酐清除率(均 P < 0.05)。Mols 治疗改善了射血分数(53 ± 3%比 Veh 治疗大鼠的 37 ± 2%,P < 0.001)和每搏量(324 ± 33 比 Veh 治疗大鼠的 255 ± 15 μl,P < 0.05)。Mols 治疗大鼠的舒张末期压力(8.5 ± 1.1 mmHg)低于 Veh 治疗大鼠(16.3 ± 3.5 mmHg,P < 0.05),松弛时间常数也较低(21.9 ± 1.8 比 30.9 ± 3.3 ms,分别,P < 0.05)。与 Veh 治疗相比,Mols 治疗使 LV 收缩末期压力-容积关系向左移位。总之,在低 NO 可利用性的心肾衰竭模型中,补充 NO 可显著改善心脏收缩和舒张功能,而对后负荷没有明显影响。