Study on circadian changes in sympathetic tone in subtotal nephrectomized rats with heart failure

我们研究了慢性肾脏病（CKD）是否可以改变心力衰竭（HF）大鼠自主神经功能的昼夜变化。大鼠接受肾次全切除术和手术诱导的心肌梗死作为心肾综合征的潜在模型。大鼠在12小时的光暗环境中适应后，用无线遥测压力传感器连续记录24 - 48小时的血压、心率和自发活动。 在觉醒期间，舒张压变异性的低频成分，交感神经张力的指数，在心衰大鼠CKD比心衰大鼠没有CKD更夸张。 通过每小时间歇性CO2暴露评估的高碳酸血症化疗敏感性在HF CKD大鼠的觉醒期间短暂增加，表明中枢化疗敏感性可能与心肾综合征中过度的交感神经紧张有关。

We studied whether chronic kidney disease (CKD) could alter circadian changes in autonomic function in rats with heart failure (HF). Rats underwent subtotal nephrectomy and surgically induced myocardial infarction as a potential model of cardiorenal syndrome. After acclimatization to a 12h light-dark cycle, blood pressure, heart rate and locomotor activity were continuously recorded for 24 - 48 hours in conscious, unrestrained rats by using instrumented radiotelemetry pressure transducer. During the awakening period, low frequency components of diastolic blood pressure variability, an index of sympathetic tone, were more exaggerated in HF rats with CKD than in HF rats without CKD. Hypercapnic chemosensitivity evaluated by hourly intermittent CO2 exposure was transiently increased during the awakening period in HF rats with CKD, suggesting that central chemosensitivity could be related to the exaggerated sympathetic tone in cardiorenal syndrome.