Effect of norepinephrine on penetrating arterioles of rat cerebral cortex.
Effect of norepinephrine on penetrating arterioles of rat cerebral cortex.
复制标题
去甲肾上腺素对大鼠大脑皮层穿通小动脉的影响。
DOI：
10.1152/ajpheart.1984.246.3.h380
复制
发表时间：
1984
期刊：
影响因子：
--
通讯作者：
Duling,BR
中科院分区：
文献类型：
--
作者：
DaceyJr,RG;Duling,BR
取平均静息直径26.3 +/- 2.8微米，最大直径37.4 +/- 2.5 （SE）微米的大鼠脑内穿透性小动脉，分离、插管、体外灌注。自发张力发育和氢离子反应性表明血管相对完好且具有活力。脑内穿透性小动脉的去甲肾上腺素（NE）反应性是pH依赖性的。在腔外pH为7.30时，血管对10(-6)M浓度的NE没有反应。当NE浓度超过10(-6)M时，血管的直径扩张到对照组的110%左右。当pH值为7.80时，当腔外NE浓度在10（-11）和10(-6)M之间时，血管收缩至对照的75 - 80%。当pH值为7.30和7.80时，10(-6)M酚妥拉明中的血管对10(-8)M NE没有反应。当pH值调整到7.30时，在pH值为7.80时组成的10(-8)M NE溶液不能诱导血管收缩，这表明NE分解产物不是收缩的原因。这些数据表明，穿透脑小动脉的肾上腺素能机制与类似大小的外周小动脉的肾上腺素能机制明显不同。
Penetrating intracerebral arterioles from the rat with mean resting diameters of 26.3 +/- 2.8 micron and maximal diameters of 37.4 +/- 2.5 (SE) micron were isolated, cannulated, and perfused in vitro. Spontaneous tone development and hydrogen ion reactivity indicated that vessels were relatively undamaged and viable. The norepinephrine (NE) reactivity of intracerebral penetrating arterioles is pH dependent. Vessels studied at extraluminal pH 7.30 were unresponsive to NE up to concentrations of 10(-6) M. At NE concentrations above 10(-6) M, vessels dilated to diameters approximately 110% of control. At pH 7.80, vessels contracted to diameters between 75 and 80% of control in response to extraluminal NE concentrations between 10(-11) and 10(-6) M. Vessels in 10(-6) M phentolamine failed to respond to 10(-8) M NE at pH 7.30 and pH 7.80. An aliquot of 10(-8) M NE solution made up at pH 7.80 failed to induce vessel contraction when the pH was readjusted to 7.30, indicating that a NE breakdown product was not responsible for the contraction. These data suggest that adrenergic mechanisms in penetrating cerebral arterioles are significantly different from those seen in peripheral arterioles of similar size.