Total and Regional Cerebral Blood Flow During Stimulation of Carotid Baroreceptors
Total and Regional Cerebral Blood Flow During Stimulation of Carotid Baroreceptors
复制标题
颈动脉压力感受器刺激期间的总脑血流量和局部脑血流量
作者：
D. Heistad;M. Marcus
最近的研究表明，颈动脉压力感受器在脑血流（CBF）的调节中起着重要作用，从而挑战了脑血管反射控制不重要的概念。在这项研究中，我们已经测试了动脉压力感受器有助于调节总CBF或区域CBF的假设。用15%微球麻醉犬测量CBF。通过提高颈动脉窦压刺激颈动脉压力感受器，不会改变或重新分配脑血流。对压力感受器刺激的反应是完整的，骨骼肌血管舒张就是证明。CBF在全身性低碳酸血症期间下降，在高碳酸血症期间增加，这表明在压力感受器刺激期间脑流量改变的失败不是由于脑血管无反应性。在高碳酸血症期间，压力感受器刺激也未能改变CBF。在其他研究中，CBF是在动脉压力感受器去神经支配之前和之后的全身动脉压升高期间测量的。无论是在压力感受器去神经支配之前还是之后，动脉压的升高都没有增加CBF。我们得出的结论是，压力感受器刺激不会改变总CBF或局部CBF，并且压力感受器不会调节全身性高血压期间的脑流量。
The concept that reflex control of cerebral vessels is unimportant has been challenged by recent studies which suggest that carotid baroreceptors have an important role in regulation of cerebral blood flow (CBF). In this study we have tested the hypothesis that arterial baroreceptors contribute to regulation of total or regional CBF. CBF was measured in anesthetized dogs with 15 % microspheres. Stimulation of carotid baroreceptors, by raising carotid sinus pressure, did not alter or redistribute cerebral flow. Responses to baroreceptor stimulation were intact, as manifested by vasodilation in skeletal muscle. CBF decreased during systemic hypocapnia and increased during hypercapnia, which indicates that failure of cerebral flow to change during baroreceptor stimulation was not due to unresponsiveness of cerebral vessels. During hypercapnia, baroreceptor stimulation also failed to alter CBF. In other studies CBF was measured during increases in systemic arterial pressure, before and after denervation of arterial baroreceptors. Increases in arterial pressure did not increase CBF either before or after denervation of baroreceptors. We conclude that baroreceptor stimulation does not alter total or regional CBF and that baroreceptors do not regulate cerebral flow during systemic hypertension.