A role of the K-channel in regulation of cerebral microcirculation

K通道在脑微循环调节中的作用

• 批准号: 09671418
• 负责人: TAKAYASU Masakazu
• 金额: $ 1.47万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09671418/
• 关键词: K-channel; Cerebral microcirculation; arterioles; ポタシュウムチャンネル

Although the K-channel is a well-known regulator of the circulation in many organs such as heart and lung, little is known about the K-channel in cerebral microcirculation. We investigated the role of K-channel in regulation of cerebral microcirculation by meauring vessel diameter and the membrane potential simultaneously in isolated cerebral arterioles. (Methods) Penetrating intracerebral arterioles, about 50 mu m in diameter, were isolated surgically from the middle cerebral arteries of male Sprague-Dawley rats, and were cannulated under the inverted microscope. After transmural pressure was set to 60 mmHg and bath temperature was brought to 37.5ﾟC, the vessels developed spontaneous tone, contracting to approximately 70% of theri maximum passive diameters. The vessel diameter and the membrane potential of the smooth muscle cells were monitored simultaneously. The membrane potential was measured through the glass electrode filled with potassium acetate, which was penetrated into the cells using an electric pulse manipulator. (Results) When glibenclamide (10 mu M), an inhibitor of ATP-sensitive K-channels, was administered, the vessel diamter decreased by 5.1*4.4% from a diameter of 59.0*13.1 mu m (n= 10) and membrane potential was depolarozed form -33*4.2 mV to -29.7*3.6 mV.On the other hand, the membrane potential did not change at all when nitric oxide synthase inhibitor (NG-monomethyl-L-arginine : 100 mu M) was administered. (Conclusion) The present study suggests that K-channel plays an important role in maintenance of basic tone of arterioles in the cerebral microcirculation.

虽然K通道是许多器官如心脏和肺中循环的众所周知的调节剂，但对脑微循环中的K通道知之甚少。本实验通过测定脑微动脉内径和膜电位，探讨了钾通道在脑微循环调节中的作用。（方法）从雄性Sprague-Dawley大鼠大脑中动脉分离出直径约50 μ m的脑内穿通小动脉，在倒置显微镜下插管。在跨壁压设定为60 mmHg，浴温升至37.5 ℃后，血管出现自发张力，收缩至最大被动直径的约70%。同时监测血管直径和平滑肌细胞膜电位。膜电位的测量是通过填充有乙酸钾的玻璃电极，使用电脉冲操纵器将其渗透到细胞中。（结果）当给予ATP敏感性K通道抑制剂格列本脲（10 μ M）时，血管直径从59.0 × 13.1 μ m（n= 10）减小5.1 × 4.4%，膜电位从-33 ~4.2 mV去极化至-29.7 ~3.6 mV。当施用一氧化氮合酶抑制剂（NG-单甲基-L-精氨酸：100 μ M）时，膜电位完全没有变化。（结论）K通道在维持脑微循环微动脉的基本张力中起重要作用。

项目成果

Kajita Y,Takayasu M,Dietrich HH,Dacey RG,Jr: "Possible role of vasodilatory propagation in the regulation of rat cerebral microcirculation." Microcirculation annual. 13. 81-84 (1997)

Kajita Y，Takayasu M，Dietrich HH，Dacey RG，Jr：“血管舒张传播在大鼠脑微循环调节中的可能作用。”

Kajita Y,Takayasu M,Dietrich HH,Dacey RG,Jr: "Possible role of nitric oxide in autoregulatory response in rat intracerebral arterioles." Neurosurgery. 42. 834-842 (1998)

Kajita Y、Takayasu M、Dietrich HH、Dacey RG、Jr：“一氧化氮在大鼠脑内小动脉自动调节反应中的可能作用。”

Mori M,Takayasu M,Suzuki Y,Shibuya M,Yoshida J,Hidaka H: "Vasodilatory effects of C-type natriuretic peptide on cerebral parenchymal arterioles in rats." Eur J Pharmacol. 320. 183-186 (1997)

Mori M，Takayasu M，Suzuki Y，Shibuya M，Yoshida J，Hidaka H：“C型利钠肽对大鼠脑实质小动脉的血管舒张作用。”

Mori M,Takayasu M,Suzuki Y,Shibuya M,Yoshida J,Hidaka H: "Effects of adrenomedullin on rat cerebral parenchymal arterioles." Eur J Pharmacol. 330. 195-198 (1997)

Mori M，Takayasu M，Suzuki Y，Shibuya M，Yoshida J，Hidaka H：“肾上腺髓质素对大鼠脑实质小动脉的影响。”

Kajita Y,Takayasu M,Dietrich HH,Dacey RG,Jr: "Vasodilatory effect of basic fibroblast growth factor in isolated rat intracerebral arterioles." Microcirculation annual. 14. 81-82 (1998)

Kajita Y，Takayasu M，Dietrich HH，Dacey RG，Jr：“碱性成纤维细胞生长因子在离体大鼠脑内小动脉中的血管舒张作用。”