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

我们研究了慢性肾脏疾病（CKD）是否会改变心力衰竭（HF）大鼠自主神经功能的昼夜变化。大鼠接受肾大部切除术和手术诱导心肌梗死作为心肾综合征的潜在模型。在适应12h的光照-黑暗周期后，在24 - 48小时内，用仪器式无线遥测压力传感器连续记录清醒、无约束大鼠的血压、心率和运动活动。在觉醒期间，伴有CKD的HF大鼠的舒张压变异性低频分量（交感神经张力指标）比无CKD的HF大鼠更为夸张。在伴有CKD的HF大鼠苏醒期间，通过每小时间歇性CO2暴露评估的高capic化学敏感性会短暂增加，这表明中枢化学敏感性可能与心肾综合征交感神经张力的夸大有关。

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.