Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.
Centro de Investigación Biomédica, Universidad Autónoma de Chile, Santiago, Chile.
Sci Rep. 2017 Aug 14;7(1):8035. doi: 10.1038/s41598-017-08142-3.
Enhanced carotid body (CB) chemoreflex function is strongly related to cardiorespiratory disorders and disease progression in heart failure (HF). The mechanisms underlying CB sensitization during HF are not fully understood, however previous work indicates blood flow per se can affect CB function. Then, we hypothesized that the CB-mediated chemoreflex drive will be enhanced only in low output HF but not in high output HF. Myocardial infarcted rats and aorto-caval fistulated rats were used as a low output HF model (MI-CHF) and as a high output HF model (AV-CHF), respectively. Blood flow supply to the CB region was decreased only in MI-CHF rats compared to Sham and AV-CHF rats. MI-CHF rats exhibited a significantly enhanced hypoxic ventilatory response compared to AV-CHF rats. However, apnea/hypopnea incidence was similarly increased in both MI-CHF and AV-CHF rats compared to control. Kruppel-like factor 2 expression, a flow sensitive transcription factor, was reduced in the CBs of MI-CHF rats but not in AV-CHF rats. Our results indicate that in the setting of HF, potentiation of the CB chemoreflex is strongly associated with a reduction in cardiac output and may not be related to other pathophysiological consequences of HF.
颈动脉体（CB）化学感受反射功能增强与心力衰竭（HF）中的心肺功能障碍和疾病进展密切相关。然而，HF 期间 CB 敏化的机制尚不完全清楚，先前的研究表明，血流量本身可能会影响 CB 的功能。因此，我们假设只有在低心输出量 HF 中，CB 介导的化学感受反射驱动力才会增强，而在高心输出量 HF 中则不会。心肌梗死大鼠和腹主动脉-腔静脉瘘大鼠分别被用作低心输出量 HF 模型（MI-CHF）和高心输出量 HF 模型（AV-CHF）。与假手术和 AV-CHF 大鼠相比，仅在 MI-CHF 大鼠中 CB 区域的血流供应减少。与 AV-CHF 大鼠相比，MI-CHF 大鼠的低氧通气反应明显增强。然而，与对照组相比，MI-CHF 和 AV-CHF 大鼠的呼吸暂停/低通气发生率均显著增加。在 CB 中，一种流量敏感的转录因子，Krüppel 样因子 2 的表达在 MI-CHF 大鼠中减少，但在 AV-CHF 大鼠中没有减少。我们的研究结果表明，在心衰状态下，CB 化学感受反射的增强与心输出量的降低密切相关，而与心衰的其他病理生理后果无关。
