Cerebral blood flow during elevation of intracranial pressure: role of sympathetic nerves.
Cerebral blood flow during elevation of intracranial pressure: role of sympathetic nerves.
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颅内压升高期间的脑血流量：交感神经的作用。
DOI：
10.1152/ajpheart.1981.241.1.h78
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Heistad,D
中科院分区：
文献类型：
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作者：
Sadoshima,S;Thames,M;Heistad,D
这项研究的目的是检查颅内压升高对脑血流量 (CBF) 的影响，并确定交感神经是否调节这种反应。通过向兔侧脑室注入人工脑脊液来升高颅内压。侧脑室和小脑延髓池的颅内压增加相似。颅内压从基线 7 毫米汞柱逐渐增加到 96 毫米汞柱，导致 CBF 逐渐减少（用微球测量）。血流量的减少是不均匀的：颅内压从 7 +/- 1 到 46 +/- 3 (SE) mmHg 的升高使大脑的血流量减少了 33 +/- 5%，而髓质的血流量仅减少了 5 +/- 2%（P 小于 0.05）。颅内压降低至正常水平会在大脑的所有区域产生明显的反应性充血。尽管颅内高压期间交感神经流量增加了五倍，但颈上神经节切除术并不影响 CBF。在其他实验中，4 Hz 频率的交感神经电刺激使流向骨骼肌的血流减少了 80%，但不影响 CBF； 15 Hz 的刺激会导致 CBF 适度减少。我们得出的结论是：1）在颅内压升高期间，尽管两个区域的颅内压相似，但髓质的血流比大脑更好地保留，2）颅内高压期间交感神经的强烈反射激活不会影响CBF。
This study was performed to examine effects of increased intracranial pressure on cerebral blood flow (CBF) and to determine if sympathetic nerves modulate this response. Intracranial pressure was raised by infusion of artificial cerebrospinal fluid into a lateral ventricle of rabbits. Increases in intracranial pressure were similar in the lateral ventricles and cisterna magna. Graded increases in intracranial pressure from base line of 7 to 96 mmHg produced graded reductions in CBF (measured with microspheres). Reductions in blood flow were heterogeneous: elevation of intracranial pressure from 7 +/- 1 to 46 +/- 3 (SE) mmHg reduced blood flow to the cerebrum by 33 +/- 5% and blood flow to the medulla by only 5 +/- 2% (P less than 0.05). Reduction of intracranial pressure to normal levels produced marked reactive hyperemia in all areas of the brain. Although sympathetic nerve traffic increased fivefold during intracranial hypertension, superior cervical ganglionectomy did not affect CBF. In other experiments, electrical stimulation of sympathetic nerves at 4 Hz reduced blood flow to skeletal muscle by 80% but did not affect CBF; stimulation at 15 Hz produced a modest reduction in CBF. We conclude that 1) during increases in intracranial pressure, blood flow is better preserved to the medulla than to the cerebrum despite similar intracranial pressure in the two areas and 2) intense reflex activation of sympathetic nerves during intracranial hypertension does not affect CBF.