血圧変動に対する脳幹血流量および脳底動脈血管径の変化における一酸化窒素の役割

一氧化氮在血压波动引起的脑干血流量和基底动脉直径变化中的作用

• 批准号: 08770463
• 负责人: 豊田 一則
• 金额: $ 0.51万
• 依托单位: Kyushu Dental College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Encouragement of Young Scientists (A)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 无数据
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-08770463/
• 关键词: 脳血流; 脳動脈; 血管拡張反応; 一酸化窒素; 血圧; 血管径; 降圧

脳底動脈とその分枝は、脳血流自動調節能の下限域付近で有意に拡張し、脳幹血流量の低下を軽減させる(研究発表1)。この調節機構における一酸化窒素(Nitric oxide;以下NO)の役割を検討した。雄Sprague-Dawleyラット脳幹に開放頭蓋窓を作成。非選択的NO合成酵素阻害薬N^ω-nitro-L-arginine(L-NA)10^<-5>mol/L(低L-NA群)・同10^<-4>mol/L(高L-NA群)・ニューロン由来NO合成酵素選択的阻害薬7nitro-indazole 10^<-5>mol/L(7NI群)・生食(対照)を局所投与し、段階的な脱血降圧下で脳幹部動脈径と局所血流量(Laser-Doppler血流計を使用)を測定した。薬剤投与により、低・高L-NA群で血流量(-11±4%、-11±3%)、脳底動脈径(-18±4%、-25±3%)、分枝径とも有意に減少したが、7NI群では変化しなかった。降圧時の脳幹血流自動調節能下限域(対照で30mmHg)は低(45mmHg)・高L-NA群(60mmHg)で上方に偏位し、7NI群では偏位しなかった。脳底動脈は対照で高度降圧時(45mmHg以下)に著明に拡張した(34±4%)が、この反応は低(16±8%)・高L-NA群(12±5%)で有意に抑制され(p<0.05、2way-ANOVA)、7NI群では抑制されなかった。分枝の反応には群間に有意差を認めなかった。以上から、内皮由来NOによる脳底動脈拡張反応が降圧時の脳幹血流量の保持に関与していることが示された。我々はさらに同じ実験系を用い、加齢に伴ってATP感受性カリウムチャネル開口に対する脳幹部動脈拡張反応が減弱すること(研究発表2)をも明らかにした。

The brachial artery is branched, the lower limit of the blood flow autoregulation ability is close to the lower limit of the arteries, and the lower limit of the blood flow in the trunk is reduced (Research Table 1). The adjustment mechanism of the adjustment mechanism is Nitric oxide (Nitric oxide; NO below). The male Sprague-Dawley is made from a stem with an open head. Non-selected NO synthesis enzyme inhibitor N^ω-nitro-L-arginine (L-NA) 10^<-5>mol/L (low L-NA group)・Same as 10^<-4>mol/L (high L-NA group)・Nitro-indazole Origin of NO synthesis enzyme selected inhibitor 7nitro-indazole 10^<-5>mol/L (7NI group), raw food (photo) was administered locally, and the arterial diameter and local blood flow (using a Laser-Doppler blood flowmeter) at each stage of blood loss were measured. The results of the drug administration, low and high L-NA group blood flow (-11±4%, -11±3%), and the diaphragm artery diameter ( -18±4%, -25±3%), the branch diameter was intentionally reduced, and the 7NI group was modified. When the pressure is lowered, the stem blood flow can be automatically adjusted in the lower limit range (30mmHg), low (45mmHg) and high L-NA group (60mmHg), and can be offset above the 7NI group. When the brachial artery is illuminated and the pressure is highly reduced (below 45mmHg), it is clear and the pressure is high (34±4%), and the reaction is low (16±8%) and high. The L-NA group (12±5%) was not intentionally suppressed (p<0.05, 2way-ANOVA), and the 7NI group was suppressed intentionally. The reaction of the branch is the recognition of the intentional difference between the groups. The reason for the above is that the endothelial origin of NO is the same as that of the endothelium, which is the main reason why the blood flow is maintained during the pressure reduction of the underlying artery. I am using the same じ実験式を用い, adding 齢に本ってATP sensitivity カリウムチャネル开The arterial tension and reaction of the mouth and trunk are weakened (Research Table 2).

项目成果

Toyoda K: "Changes in arterioles,arteries,and local perfusion of the brain stem during heniorrhagic hypotension." Am.J.Physiol.270. H1350-H1354 (1996)

Toyoda K：“出血性低血压期间小动脉、动脉和脑干局部灌注的变化。”

Toyoda K: "Medial medullary infarction : Analysis of eleven patients." Neurology. 47. 1141-1147 (1996)

Toyoda K：“内侧髓质梗塞：11 名患者的分析。”