Dilator response of rat mesenteric arcading arterioles to increased blood flow velocity.
Dilator response of rat mesenteric arcading arterioles to increased blood flow velocity.
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大鼠肠系膜拱形小动脉扩张器对血流速度增加的反应。
DOI：
10.1152/ajpheart.1989.257.6.h1958
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Johnson,PC
中科院分区：
文献类型：
--
作者：
Smiesko,V;Lang,DJ;Johnson,PC
大鼠肠系膜中连接相邻三角形血管段的弓状小动脉(平均直径68微米)在活体中被检测是否存在血流依赖性血管扩张。当其中一支供血动脉闭塞时，受累扇区由弓状小动脉的侧支供血，微动脉内红细胞速度增加10~66 mm/S，继之以弓状小动脉扩张(平均延时7.7 S)，平均扩张率为68%。扩张度与红细胞流速(r=0.96)、体积流量(r=0.96)、切变率(r=0.89)密切相关。这种扩张持续速度增加的时间(1-10min)，当微动脉的血流方向颠倒时，这种扩张不受影响。血流诱导的扩张等于外用罂粟碱所达到的最大扩张。如果在闭塞供血动脉的过程中也闭塞小动脉，则弓状小动脉的扩张几乎可以完全消除。这些观察表明，大鼠肠系膜弓状小动脉存在一种强有力的血流依赖性扩张器机制，并可能在局部调节中发挥重要作用。
Arcading arterioles (average diam 68 microns ID) connecting adjacent triangular vascular sectors in the rat mesentery were examined in vivo for the presence of flow-dependent vasodilation. When a feed artery to one of these sectors was occluded, the affected sector was supplied by collateral flow through the arcading arteriole, and red cell velocity in the arteriole increased by 10-66 mm/s. The velocity increase was followed (with an average delay of 7.7 s) by dilation of the arcading arteriole, which averaged 68%. The dilation was closely correlated with red cell velocity (r = 0.96), volume flow (r = 0.96), and wall shear rate (r = 0.89). The dilation was sustained for the duration of increased velocity (1-10 min) and was not affected when direction of flow in the arteriole was reversed. The flow-induced dilation was equal to the maximal dilation attained with topically applied papaverine. Dilation of the arcading arteriole could be almost completely abolished if the arteriole was also occluded during occlusion of a feed artery. These observations indicate that a potent flow-dependent dilator mechanism is present in arcading arterioles of rat mesentery and may play an important role in local regulation.