Rosendorff C, Mitchell G, Scriven D R, Shapiro C
Circ Res. 1976 Mar;38(3):140-5. doi: 10.1161/01.res.38.3.140.
We have attempted to evaluate the role of adrenergic nerves which arise from the superior cervical ganglia or which are intracerebral throughout their course, in the control of local cerebral blood flow (CBF). Hypothalamic blood flow (HBF) was measured in the conscious rabbit by the 133Xe-clearance technique. Stimulation of the upper brainstem, using 5-Hz, 3-V, 1-msec, square wave pulses, increased by HBF by a mean of 7.6 ml/100 g per min (P less than 0.005). This effect was abolished by the intrahypothalamic injection of the beta-adrenoreceptor blocker, propranolol, and by chemical sympathectomy of the hypothalamus or of the upper brainstem with 6-hydroxydopamine, but was not altered by bilateral cervical ganglionectomy. Intrahypothalamic injection of 0.1 mug of tyramine caused a mean decrease in HBF of 15.6 ml/100 g per min (P less than 0.001). This effect of intrahypothalamic injection of tyramine was abolished by bilateral cervical sympathectomy but not by chemical sympathectomy of the upper brainstem. These results support the idea that local CBF, at least in the hypothalamus, is mediated by two distinct pathways. The first consists of the sympathetic nerves which arise in the cervical ganglia, and which activate intrahypothalamic alpha-receptors to cause constriction. The second is an entirely intracerebral noradrenergic pathway which stimulates beta-receptors to cause vasodilation.
我们试图评估源自颈上神经节或全程位于脑内的肾上腺素能神经在局部脑血流（CBF）控制中的作用。通过¹³³Xe清除技术在清醒兔中测量下丘脑血流（HBF）。使用5赫兹、3伏、1毫秒的方波脉冲刺激上脑干，使HBF平均增加7.6毫升/100克每分钟（P<0.005）。下丘脑内注射β-肾上腺素能受体阻滞剂普萘洛尔、用6-羟基多巴胺对下丘脑或上脑干进行化学交感神经切除术可消除这种效应，但双侧颈神经节切除术不会改变这种效应。下丘脑内注射0.1微克酪胺导致HBF平均降低15.6毫升/100克每分钟（P<0.001）。双侧颈交感神经切除术可消除下丘脑内注射酪胺的这种效应，但上脑干化学交感神经切除术不能消除。这些结果支持这样一种观点，即局部CBF，至少在下丘脑，是由两条不同的途径介导的。第一条途径由起源于颈神经节的交感神经组成，这些交感神经激活下丘脑内的α-受体以引起血管收缩。第二条途径是完全位于脑内的去甲肾上腺素能途径，它刺激β-受体以引起血管舒张。
