肺动脉去神经术对肺动脉压正常犬局部肾素-血管紧张素-醛固酮系统的影响

Effects of pulmonary artery denervation on the renin-angiotensin-aldosterone system in pulmonary and right ventricular tissues in dogs with normal pulmonary pressure

目的探讨肺动脉去神经术对肺动脉在神经系统以外的影响。方法8~10月龄36条健康比格犬,雌雄不限,体重8~15 kg,随机分6组(每组6只),分为空白对照组、术后即刻组、术后1、2和3个月组、肺动脉高压组。空白对照组不作处理,手术组进行肺动脉去神经术,分别在术后即刻、术后1、2和3个月处死实验动物,肺动脉高压组使用脱氢野百合碱诱导犬肺动脉高压的形成,2个月后处死实验动物。取犬的右心室和肺组织,用蛋白免疫印迹杂交法半定量检测犬肺组织及右心组织血管紧张素Ⅱ(AngⅡ)、血管紧张素转换酶抑制剂1(ACE1)、血管紧张素转换酶抑制剂2(ACE2)、醛固酮抗体的蛋白表达,RT-qPCR方法检测犬肺组织及右心组织血管紧张素Ⅱ受体-1的mRNA表达情况,并计算ACE2/ACE比值,对比犬右心室和肺组织在肺动脉去神经术后肾素-血管紧张素-醛固酮系统(RAAS)的变化情况。结果肺去神经术后即刻,肺组织AngⅡ、ACE2、醛固酮受体(MR)、血管紧张素受体1(AT-1)受体同时出现升高(P=0.03、0.03、0.01和P<0.01),ACE降低(P<0.001),RAAS激活;至术后3个月,肺组织内AngⅡ降低(P=0.030),ACE2,ACE、MR、AT-1受体表达差异无统计学意义(P=0.67、0.570、0.180和0.349)。右心室ACE2表达升高(P=0.0161),Ang Ⅱ、ACE、MR、AT-1受体表达则未见明显差异(P=0.641、0.134、0.227和0.33)。结论肺动脉去神经术后即刻正常犬局部组织中的RAAS系统可被激活,至术后3个月,损伤性因子在肺内表达减少,血管保护性因子在右心室表达增加。

Objective To investigate the effects of pulmonary artery denervation(PADN)on pulmonary artery function outside of the nervous system. Methods Thirty-six beagles of 8-10 months old weighting 8-15 kg were randomized into six groups: a blank control group, an immediate post-surgery group, a 1 month post-surgery group, a 2 months post-surgery group, a 3 month post-surgery group, and a pulmonary artery hypertension(PAH)group, with six dogs in each group.Dogs in the blank control group received no treatment, and dogs in the surgery groups were treated with PADN and were then killed immediately after surgery, at 1, 2 or 3 months after surgery.PAH dogs were induced by dehydromonocrotaline, and they were killed at 8 weeks after treatment.Protein levels of angiotensin Ⅱ(Ang Ⅱ), angiotensin converting enzyme(ACE), angiotensin converting enzyme 2(ACE2), mineralocorticoid receptors(MR)and antibodies against aldosterone in dog pulmonary and right ventricular tissues were detected by Western blot.The mRNA expression of the Ang Ⅱ type 1 receptor(AT1R)was determined by real-time reverse transcription quantitative polymerase chain reaction(RT-qPCR). The protein expression ratio of ACE2 to ACE in lung and right ventricular tissues were calculated.Changes of the renin-angiotensin-aldosterone system(RAAS)in lung and right ventricular tissues were compared between the groups. Results In pulmonary tissues, protein levels of Ang Ⅱ, ACE2, MR, and AT-1R increased immediately after PADN(P=0.03, 0.03, 0.01 and<0.01), and the protein expression of ACE decreased(P<0.001), indicating that RAAS was activated immediately after PADN.Three months after PADN, AngⅡ protein levels declined significantly in lung tissues(P=0.030), and ACE2, ACE, MR, and AT-1 receptor protein expression had no obvious difference(P=0.670, 0.570, 0.180 and 0.349), compared with the blank control group.In right ventricular tissues, the protein expression of ACE2 was higher in the surgery groups than in the blank control group(P=0.0161), and there was no significant difference in the protein expression of Ang Ⅱ, ACE, MR, and AT-1 receptors(P=0.641, 0.134, 0.227 and 0.330). Conclusions RAAS activates immediately in dogs with normal pulmonary pressure after PADN, the damaging factors in pulmonary tissues are reduced and the vascular protective factors in right ventricular tissues are elevated at 3 months after PADN.