Bagshaw R J, Cox R H, Karreman G, Newswanger J
J Appl Physiol (1985). 1986 Jan;60(1):166-75. doi: 10.1152/jappl.1986.60.1.166.
In the absence of peripheral chemoreceptors, the effects of graded hypoxemia on the carotid sinus control of central and regional hemodynamics were studied in anesthetized mongrel dogs. Baroreceptor stimulation was effected by carotid sinus isolation and perfusion under controlled pressure. Blood flows were measured in the aorta and the celiac, mesenteric, left renal, and right iliac arteries. Carotid sinus reflex set-point pressures were well maintained until hypoxemia was severe. Carotid sinus reflex set-point gain was maximal during mild hypoxemia. Reflex operating point regional flows were unaffected by hypoxemia. A factorial analysis of overall reflex increases in mean aortic pressure, flow, and power during reduced baroreceptor stimulation showed potentiation by increasing hypoxemia. Corresponding effects of baroreceptor stimulation and hypoxemia on aortic resistance and heart rate were additive. Celiac, renal, and iliac blood flows increased during both hypoxemia and reduced baroreceptor stimulation. Only in the celiac bed were blood flow changes independent of concomitant changes in cardiac output. Thus, at maximum sympathetic stimulation (low carotid sinus pressure) during hypoxemia, the cardiovascular system maintained both central and regional blood flows at high systemic blood pressures independent of the peripheral chemoreceptors.
在没有外周化学感受器的情况下，在麻醉的杂种犬中研究了分级低氧血症对颈动脉窦控制中枢和局部血流动力学的影响。通过在控制压力下进行颈动脉窦分离和灌注来实现压力感受器刺激。测量主动脉以及腹腔、肠系膜、左肾和右髂动脉的血流。在严重低氧血症之前，颈动脉窦反射设定点压力保持良好。在轻度低氧血症期间，颈动脉窦反射设定点增益最大。反射工作点局部血流不受低氧血症影响。在压力感受器刺激减少期间，对平均主动脉压、血流和功率的总体反射增加进行的析因分析表明，随着低氧血症加重，存在增强作用。压力感受器刺激和低氧血症对主动脉阻力和心率的相应影响是相加的。在低氧血症和压力感受器刺激减少期间，腹腔、肾和髂血流均增加。只有在腹腔床，血流变化与心输出量的伴随变化无关。因此，在低氧血症期间最大交感神经刺激（低颈动脉窦压力）时，心血管系统在高体循环血压下维持中枢和局部血流，而与外周化学感受器无关。
