肾交感神经射频消融术对高血压犬去甲肾上腺素溢出率及交感神经活性的影响

摘要

目的 评价肾交感神经射频消融术(RSD)治疗腹主动脉缩窄型高血压犬的有效性和作用机制.方法 成年健康杂种犬20只,采用腹主动脉缩窄法建立高血压模型.模型建立后,随机分为治疗组(n=10)和对照组(n=10).治疗组犬于建模后1个月行双侧肾交感神经射频消融术.分别于建立模型前和建立模型后1、2、3个月,测定犬前上臂血压、交感神经活性及去甲肾上腺素溢出率并观察其变化趋势.结果 建模后1个月,对照组前上臂收缩压(SBP)、舒张压(DBP)和平均动脉压(MAP)与建模前比较均明显升高(P＜0.05),肾交感神经活性冲动明显增强,去甲肾上腺素溢出率水平明显增高(P＜0.05).治疗组RSD手术即刻肾交感神经活性明显下降,至消融后2个月略有增高；去甲肾上腺素溢出率水平在建模后1个月显著增高(P＜0.05),消融后显著降低并一直持续至实验结束(P＜0.05).与对照组比较,治疗组消融后1个月、2个月去甲肾上腺素溢出率水平显著降低(P＜0.05).结论 RSD对于高血压犬去甲肾上腺素溢出率及交感神经活性均有明显抑制作用.%Objective To evaluate the validity and explore the mechanism of renal sympathetic denervation (RSD) in the treatment of dogs with hypertension reproduced by constriction of abdominal aorta. Methods The hypertension model was reproduced by constriction of abdominal aorta in 20 adult healthy dogs. These dogs were then randomly divided into the treatment group and control group (10 each). Renal sympathetic nerve radiofrequency ablation was done in treatment group 1 month after modeling. The foreleg blood pressure, sympathetic activity and norepinephrine overflow rate of dogs in two groups were detected before modeling, and 1, 2 and 3 months after modeling, and the trend of the change was also observed. Results One month after modeling, the systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial blood pressure (MAP) were elevated significantly in control group (146.7 ± 21.0, 89.0 ± 12.7 and 108.3 ± 14.9mmHg) compared with those before modeling (119.5 ± 13.2, 76.5 ± 7.8 and 90.9 ± 8mrnHg, P<0.05). The renal sympathetic activity impulse and norepinephrine spillover rate were also enhanced significantly (P<0.05). The renal sympathetic nerve activity obviously decreased in the treatment group after the operation, and then increased 2 months after the ablation. The norepinephrine spillover rate in treatment group increased significantly 1 month after modeling (P<0.05), and decreased after ablation, and it lasted to the end of the experiment (P<0.05). One and two months after ablation, the norepinephrine spillover rate was lower in treatment group than in control group (P<0.05). Conclusion Renal sympathetic nerve radiofrequency ablation significantly inhibits the elevation of norepinephrine spillover rate and sympathetic nerve activity in dogs with hypertension.