Elevated renal afferent nerve (ARNA) activity or dysfunctional reno-renal reflexes via altered ARNA sensitivity contribute to hypertension and chronic kidney disease. These nerves contain mechano- and chemo-sensitive fibers that respond to ischemia, changes in intrarenal pressures, and chemokines. Most studies have utilized various anesthetized preparations and exclusively male animals to characterize ARNA responses. Therefore, this study assessed the impact of anesthesia, sex, and circadian period on ARNA responses and sensitivity. Multifiber ARNA recordings were performed in male and female Sprague-Dawley rats (250-400 g) and compared across decerebrate versus Inactin, isoflurane, and urethane anesthesia groups. Intrarenal artery infusion of capsaicin (0.1 μM - 50.0 μM, 0.05 mL) produced concentration-dependent increases in ARNA; however, the ARNA sensitivity was significantly greater in decerebrate versus Inactin, isoflurane, and urethane groups. Increases in renal pelvic pressure (0 - 30 mmHg, 30s) produced pressure-dependent increases in ARNA; however, ARNA sensitivity was again greater in decerebrate and Inactin groups versus isoflurane and urethane. Acute renal artery occlusion (30s) increased ARNA, but responses did not differ across groups. Analysis of ARNA responses to increased pelvic pressure between male and female rats revealed significant sex differences only in isoflurane and urethane groups. ARNA responses to intrarenal capsaicin infusion were significantly blunted at nighttime versus daytime; however, ARNA responses to increased pelvic pressure or renal artery occlusion were not different between daytime and nighttime. These results demonstrate that ARNA sensitivity is greatest in decerebrate or Inactin anesthetized groups but was not consistently influenced by sex.

中文翻译：

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麻醉、性和昼夜节律对肾传入神经敏感性的影响


肾传入神经 (ARNA) 活性升高或 ARNA 敏感性改变导致肾病肾反射功能障碍，导致高血压和慢性肾脏病。这些神经含有对缺血、肾内压力变化和趋化因子做出反应的机械和化学敏感纤维。大多数研究都使用各种麻醉制剂并专门使用雄性动物来表征 ARNA 反应。因此，本研究评估了麻醉、性别和昼夜节律对 ARNA 反应和敏感性的影响。在雄性和雌性 Sprague-Dawley 大鼠（250-400 g）中进行多纤维 ARNA 记录，并在去脑麻醉组与 Inactin、异氟烷和聚氨酯麻醉组之间进行比较。肾动脉内输注辣椒素（0.1 μM - 50.0 μM，0.05 mL）可产生浓度依赖性的 ARNA 增加；然而，去大脑组的 ARNA 敏感性明显高于 Inactin、异氟烷和氨基甲酸酯组。肾盂压力增加（0 - 30 mmHg，30 秒）会导致 ARNA 随压力而增加；然而，与异氟烷和氨基甲酸乙酯组相比，去大脑和 Inactin 组的 ARNA 敏感性再次更高。急性肾动脉闭塞（30 秒）会增加 ARNA，但各组的反应没有差异。对雄性和雌性大鼠之间骨盆压力增加的 ARNA 反应的分析表明，仅在异氟烷组和氨基甲酸乙酯组中存在显着的性别差异。与白天相比，夜间 ARNA 对肾内辣椒素输注的反应显着减弱；然而，ARNA 对骨盆压力增加或肾动脉闭塞的反应在白天和夜间没有差异。 这些结果表明，ARNA 敏感性在去大脑或 Inactin 麻醉组中最高，但并不受性别的一致影响。