血管紧张素Ⅱ1型受体自身抗体在甲亢大鼠心肌肥大中的作用及其与PI3K/Akt信号通路的关系

目的 观察甲亢心肌肥大大鼠血清血管紧张素Ⅱ1型受体自身抗体（AT₁-AA）与心肌组织磷脂酰肌醇-3-激酶（PI3K）、蛋白激酶B（Akt）的表达，探讨AT₁-AA在甲亢大鼠心肌肥大中的作用及其与PI3K/Akt信号通路的关系。方法 将54只SD大鼠随机分为3组：甲亢组、甲亢+奥美沙坦组及对照组，每组18只，前2组灌服左甲状腺素钠制备甲亢大鼠模型，甲亢+奥美沙坦组同时给予奥美沙坦。以心脏质量指数（HWI）和心钠肽（ANP）mRNA作为心肌肥大指标，采用酶联免疫吸附法（ELISA）检测大鼠血清AT₁-AA，并通过蛋白质印迹法检测各组大鼠血管紧张素Ⅱ1型受体（AT₁R）和PI3K/p-Akt的表达水平；根据AT₁-AA检测结果，将甲亢组和甲亢+奥美沙坦组大鼠分为AT₁-AA阳性组和阴性组，比较AT₁-AA阳性组和阴性组AT₁R及PI3K/p-Akt的表达情况。结果 （1）与对照组比较，甲亢组、甲亢+奥美沙坦组大鼠HWI增加，ANP mRNA相对表达量升高（P均<0.05）；甲亢组大鼠HWI及ANP mRNA相对表达量亦高于甲亢+奥美沙坦组大鼠（P<0.05）。（2）甲亢组、甲亢+奥美沙坦组大鼠AT₁-AA 阳性率及光密度（D）值（61.11%，72.22%和0.44±0.12，0.49±0.08）高于对照组（16.67%和0.28±0.05，P均<0.01）。（3）甲亢组、甲亢+奥美沙坦组大鼠AT₁R和PI3K/p-Akt的表达较对照组升高（P<0.05，P<0.01）；与甲亢组相比，甲亢+奥美沙坦组大鼠心肌组织PI3K、p-Akt表达水平均降低（P<0.01，P<0.05）。（4）甲亢组大鼠中，AT₁-AA阳性组PI3K/p-Akt的表达明显高于AT₁-AA阴性组（P<0.01）；甲亢+奥美沙坦组大鼠中，AT₁-AA阳性组PI3K/p-Akt的表达较AT₁-AA阴性组降低（P<0.05）。结论 AT₁-AA可能通过AT₁R激活PI3K/Akt信号通路参与甲亢心肌肥大病理生理过程。

Relationship between autonomic nervous system and early recurrence of atrial fibrillation after radiofrequency catheter ablation

Objective To investigate the relationship between autonomic nervous reflex and early recurrence of atrial fibrillation after radiofrequency catheter ablation (RFCA) using diving reflex test and cold pressor test. Methods A total of 102 patients with paroxysmal atrial fibrillation were recruited in the present study. All patients underwent diving reflex test and cold pressor test before and after RFCA. The relationship between mean heart rate and early recurrence of atrial fibrillation was observed. Results Circumferential pulmonary vein isolation was successfully achieved in all the 102 patients. The mean heart rate was decreased by diving reflex test and increased by cold pressor test. The diving reflex of the participants was significantly decreased after RFCA (P<0.05), and the cold pressor test results had no noticeable change. The diving reflex in patients with early recurrence of atrial fibrillation was more intensive than those without (P<0.05). Conclusion The parasympathetic activity is decreased in atrial fibrillation patients after RFCA, and the decrease may be related to the early recurrence of atrial fibrillation after RECA.