Rogulatory mechanism of Cerebral microcirculation

脑微循环的调节机制

• 批准号: 08670724
• 负责人: TANAHASHI Norio
• 金额: $ 1.41万
• 依托单位: KEIO University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08670724/
• 关键词: cerebral circulation; Neuropeptide Y; Photoelectric method; nitric oxide; 光電法; Neuropetpide-Y(NPY)

The effects of intracarotidly injected neuropeptide Y (NPY ; 0.1 mug/kg) on the local cerebral blood volume (CBV) and blood flow (CBF) in the parietotemporal cortex were examined by the photoelectric method in 17 anesthetized cats. CBV reflects the cumulative crosssectional area of the cerebral microvascular beds. NPY immediately caused transient but significant increase in CBV and CBF,which lasted for less than 5 min. Thereafter, CBV returned to and remained at the control level, although CBF was decreased by 30-40% for 60 min during the monitoring period. The CBV increases after NPY were prevented by a 15-min preinjection of 0.35 mg/kg/min of N^G-monomethyl-L-arginine (L-NMMA), which is a competitive blocker of nitric oxide synthesis. The CBV increases after NPY reappeared following a 15-min administration of 0.25 mg/kg/min of L-arginine, which is a precursor of nitric oxide. We conclude that NPY administered in vivo exerts a previously unreported effect of transient vasodilatation on the cerebral microvessels. This action appears to be mediated by mitric oxide, which is a major candidate as an endothelium-derived relaxing factor (EDRF).

采用光电法观察17只麻醉猫颈动脉内注射神经肽Y （NPY; 0.1 mug/kg）对顶叶皮层局部脑血容量（CBV）和血流量（CBF）的影响。CBV反映了脑微血管床的累积横截面积。NPY立即引起CBV和CBF短暂但显著的增加，持续时间不到5分钟。此后，CBV恢复并保持在控制水平，尽管在监测期间的60分钟内CBF下降了30-40%。NPY后CBV的增加可通过预注射0.35 mg/kg/min的N^ g -单甲基- l-精氨酸（L-NMMA） 15 min来阻止，N^ g -单甲基- l-精氨酸是一氧化氮合成的竞争性阻滞剂。0.25 mg/kg/min的l -精氨酸（一氧化氮的前体）给药15分钟后，NPY再次出现，CBV增加。我们的结论是，体内给药NPY对大脑微血管有一种以前未报道的短暂性血管舒张作用。这种作用似乎是由三氧化二氮介导的，三氧化二氮是内皮源性放松因子（EDRF）的主要候选者。