Effect of jugular venous pressure on cerebral autoregulation in dogs.
Effect of jugular venous pressure on cerebral autoregulation in dogs.
复制标题
颈静脉压对犬脑自动调节的影响。
DOI：
10.1152/ajpheart.1988.255.6.h1516
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Traystman,RJ
中科院分区：
文献类型：
--
作者：
McPherson,RW;Koehler,RC;Traystman,RJ
我们通过评估脑灌注压（CPP）降低时血管透壁压对脑血流量（CBF）的影响，确定了脑自动调节肌源性传感器的重要性。通过降低动脉压（Pa）或增加颅内压（Pcsf）降低CPP会降低跨壁压，而增加颈静脉压（Pcsf）会增加跨壁压。使用放射性标记的微球在巴比妥酸盐麻醉的狗中测量局部CBF。在第1组（n = 5）中，CPP随着Pa的降低而降低;在第2组（n = 5）中，CPP随着Pcsf（Pa = 80 mmHg）的增加而降低;在第3组（n = 5）中，CPP随着Pcsf（Pa = 80 mmHg）的增加而降低。每组的CPP以10 mm的增量从80 mmHg降至30 mmHg。在第1组和第2组中，当CPP降至40 mmHg时，局部CBF保持不变;然而，在CPP为30 mmHg时，流向大脑、尾状核和脑室周围白色物质的血流减少，而流向小脑和延髓的血流保持不变。在第3组中，随着CPP从80 mmHg降至50 mmHg，局部CBF不变，但随着CPP进一步降低，所有区域的CBF均降低。在所有三组中，脑血管阻力随着CPP的降低而持续下降。在所有组中，脑O2摄取均未改变。与Pa降低或Pcsf增加相比，PCSF增加时CPP更高，自动调节失败，特别是在脑干中。我们的结论是，代谢自动调节占主导地位的生肌机制，直到CPP是低的。
We determined the importance of a myogenic sensor of cerebral autoregulation by assessing the effect of vascular transmural pressure on cerebral blood flow (CBF) as cerebral perfusion pressure (CPP) was decreased. Decreasing CPP by decreased arterial pressure (Pa) or increased intracranial pressure (Pcsf) decreases transmural pressure, whereas increased jugular venous pressure (Pjv) increases transmural pressure. Regional CBF was measured in barbiturate-anesthetized dogs using radiolabeled microspheres. In group 1 (n = 5), CPP was decreased by decreasing Pa; in group 2 (n = 5), CPP was decreased by increasing Pcsf (Pa = 80 mmHg); and in group 3 (n = 5) CPP was decreased by increasing Pjv (Pa = 80 mmHg). CPP was reduced from 80 to 30 mmHg in 10-mm increments in each group. In groups 1 and 2 regional CBF was maintained as CPP was decreased to 40 mmHg; however, at CPP of 30 mmHg, blood flow to cerebrum, caudate, and periventricular white matter decreased, whereas flow to cerebellum and medulla remained unchanged. In group 3 regional CBF was unchanged as CPP decreased from 80 to 50 mmHg but decreased in all regions as CPP decreased further. In all three groups, cerebrovascular resistance continuously declined as CPP was decreased. In all groups, cerebral O2 uptake was unaltered. Autoregulation fails at a higher CPP with increased Pjv than with decreased Pa or increased Pcsf, particularly in brain stem. We conclude that metabolic autoregulation predominates over the myogenic mechanism until CPP is low.