Role of locus coeruleus in cerebral circulation and catecholamine metabolism

（1）蓝斑神经元活动对高碳酸血症引起的脑血流动力学变化有反应，当吸入CO_2时，蓝斑同侧大脑皮质组织血流量明显增加。动作电位的频率在开始吸入CO2后逐渐增加，并在40秒时达到显著水平，最大值为147（±）SY。（）50秒时为对照值的22%。停止CO2吸入诱导的动作电位的频率逐渐恢复到对照水平。（2）刺激蓝斑引起脑实质内血管收缩，刺激侧脑血容量（CBV）在20 Hz刺激开始后逐渐减少，80秒时达显著水平，最大值为-0.15（±）SY。（）在140秒时为对照值的0.05vol%（p<0.05）。对侧的CBV也显著降低。50 Hz刺激也导致双侧CBV降低。（3）蓝斑改变蛛网膜下腔出血后脑实质内血管收缩活动，刺激蓝斑时CBV显著降低，与对照值（6.3vol %）相比降低0.14 ± 0.00SY。（）80秒时0.04体积%（p<0.05），0.15（）SY. ±.（）在120秒时为0.03体积%。刺激停止后，CBV逐渐恢复。（4）用微透析技术分析脑皮层灌流液中的儿茶酚胺。我们成功地在同一样品中检测到去甲肾上腺素、多巴胺、DOPAC、HVA、5-羟色胺和5-HIAA。

(1)Neuronal activities in locus ceruleus respond to cerebral homodynamic changes induced by hypercapnia.When CO2 inhalation was applied, the significant increase in blood flow of the cerebral cortical tissue ipsilateral to the locus ceruleus was observed. The frequency of action potentials showed a gradual increase following the start of CO2 inhalation and reached a significant level by 40 seconds with maximum of 147 (〕SY.+-.〔) 22 % of the control value at 50 seconds. The cessation of CO2 inhalation induced a gradual recovery in the frequency of the action potential to the control level.(2)Cerebral intraparenchymal vasoconstriction induced by locus ceruleus stimulation.Cerebral blood volume(CBV) on the stimulated side gradually decreased following the start of 20Hz stimulation and reached a significant level by 80 seconds with a maximum of -0.15 (〕SY.+-.〔) 0.05vol% of the control value(p<0.05) at 140 seconds. CBV on the contralateral side was also reduced significantly. 50 Hz stimulation also resulted in a reduction in CBV bilaterally.(3)Locus ceruleus alters intraparenchymal vasoconrtrictive activities following subarachnoid hemorrhage.The CBV deresased significantly during the stimulation of locus ceruleus ; the decrease from the control value(6.3 vol%) was 0.14 (〕SY.+-.〔) 0.04 vol% at 80 seconds(p<0.05), 0.15 (〕SY.+-.〔) 0.03 vol% at 120 seconds. After the cessation of the stimulation, CBV showed a gradual recovery.(4)Catecholamine analysis by microdialysis technique.Perfusate from the cerebral cortex using microdialysis was analyzed by using high pressure liquid chromatography. We succeed in detectig norepinephrine, dopamine, DOPAC, HVA, serotonin, and 5-HIAA in same sample.